public override WTableReference ToTableReference()
{
WSelectQueryBlock queryBlock = SubqueryContext.ToSelectQueryBlock();
queryBlock.SelectElements.Clear();
queryBlock.SelectElements.Add(SqlUtil.GetSelectScalarExpr(SqlUtil.GetFunctionCall(GremlinKeyword.func.Mean, SubqueryContext.PivotVariable.GetDefaultProjection().ToScalarExpression()), GremlinKeyword.TableDefaultColumnName));
return(SqlUtil.GetDerivedTable(queryBlock, GetVariableName()));
}
internal static WQueryDerivedTable GetDerivedTable(WSelectQueryBlock selectQueryBlock, string alias)
{
return(new WQueryDerivedTable()
{
QueryExpr = selectQueryBlock,
Alias = GetIdentifier(alias)
});
}
public override WTableReference ToTableReference()
{
WSelectQueryBlock firstQueryExpr = new WSelectQueryBlock();
foreach (var projectProperty in ProjectedProperties)
{
if (projectProperty == GremlinKeyword.TableDefaultColumnName)
{
firstQueryExpr.SelectElements.Add(SqlUtil.GetSelectScalarExpr(InputVariable.GetDefaultProjection().ToScalarExpression(),
GremlinKeyword.TableDefaultColumnName));
}
else if (InputVariable.ProjectedProperties.Contains(projectProperty))
{
firstQueryExpr.SelectElements.Add(
SqlUtil.GetSelectScalarExpr(
InputVariable.GetVariableProperty(projectProperty).ToScalarExpression(), projectProperty));
}
else
{
firstQueryExpr.SelectElements.Add(
SqlUtil.GetSelectScalarExpr(SqlUtil.GetValueExpr(null), projectProperty));
}
}
WSelectQueryBlock secondQueryExpr = OptionalContext.ToSelectQueryBlock();
bool HasAggregateFunctionAsChildren = false;
foreach (var variable in OptionalContext.TableReferences)
{
if (variable is GremlinFoldVariable ||
variable is GremlinCountVariable ||
variable is GremlinMinVariable ||
variable is GremlinMaxVariable ||
variable is GremlinSumVariable ||
variable is GremlinMeanVariable ||
variable is GremlinTreeVariable)
{
HasAggregateFunctionAsChildren = true;
}
var group = variable as GremlinGroupVariable;
if (group != null && group.SideEffectKey == null)
{
HasAggregateFunctionAsChildren = true;
}
}
var WBinaryQueryExpression = SqlUtil.GetBinaryQueryExpr(firstQueryExpr, secondQueryExpr);
List <WScalarExpression> parameters = new List <WScalarExpression>();
parameters.Add(SqlUtil.GetScalarSubquery(WBinaryQueryExpression));
var tableRef = SqlUtil.GetFunctionTableReference(GremlinKeyword.func.Optional, parameters, GetVariableName());
((WOptionalTableReference)tableRef).HasAggregateFunctionAsChildren = HasAggregateFunctionAsChildren;
return(SqlUtil.GetCrossApplyTableReference(tableRef));
}
internal static WSelectQueryBlock GetSimpleSelectQueryBlock(params GremlinVariableProperty[] projectProperties)
{
var queryBlock = new WSelectQueryBlock();
foreach (var property in projectProperties)
{
queryBlock.SelectElements.Add(GetSelectScalarExpr(property.DefaultVariableProperty().ToScalarExpression()));
}
return(queryBlock);
}
/// <summary>
/// Returns true if there are columns of a specific table referenced in a statement
/// </summary>
/// <param name="node">The query statement</param>
/// <param name="tableName">the table for query</param>
/// <param name="context">Sql context with table alias mapping</param>
/// <param name="columnsOfNodeTables"></param>
/// <param name="conn">A open Sql connection</param>
/// <returns></returns>
public bool Invoke(WSelectQueryBlock node, string tableName, WSqlTableContext context,
Dictionary <Tuple <string, string>, Dictionary <string, NodeColumns> > columnsOfNodeTables)
{
_tableExists = false;
_tableName = tableName;
_tableRef = context[tableName] as WNamedTableReference;
_columnTableMapping = context.GetColumnTableMapping(columnsOfNodeTables);
node.Accept(this);
return(_tableExists);
}
/// <summary>
/// Returns true if there are columns of a specific table referenced in a statement
/// </summary>
/// <param name="node">The query statement</param>
/// <param name="tableName">the table for query</param>
/// <param name="context">Sql context with table alias mapping</param>
/// <param name="columnsOfNodeTables"></param>
/// <param name="conn">A open Sql connection</param>
/// <returns></returns>
public bool Invoke(WSelectQueryBlock node, string tableName, WSqlTableContext context,
Dictionary<Tuple<string, string>, Dictionary<string, NodeColumns>> columnsOfNodeTables)
{
_tableExists = false;
_tableName = tableName;
_tableRef = context[tableName] as WNamedTableReference;
_columnTableMapping = context.GetColumnToAliasMapping(columnsOfNodeTables);
node.Accept(this);
return _tableExists;
}
internal static WQueryDerivedTable GetDerivedTable(WSelectQueryBlock selectQueryBlock, string alias)
{
return(new WQueryDerivedTable()
{
QueryExpr = selectQueryBlock,
Alias = GetIdentifier(alias),
Low = Int32.MinValue,
High = Int32.MaxValue
});
}
public override void Visit(WSelectQueryBlock node)
{
if (node.SelectElements.Any(e => e is WSelectStarExpression))
{
_tableExists = true;
}
else
{
base.Visit(node);
}
}
public override WTableReference ToTableReference()
{
List <WScalarExpression> parameters = new List <WScalarExpression>();
WSelectQueryBlock selectQueryBlock = ProjectContext.ToSelectQueryBlock(true);
parameters.Add(SqlUtil.GetScalarSubquery(selectQueryBlock));
parameters.Add(SqlUtil.GetValueExpr(SideEffectKey));
var tableRef = SqlUtil.GetFunctionTableReference(GremlinKeyword.func.Store, parameters, GetVariableName());
return(SqlUtil.GetCrossApplyTableReference(tableRef));
}
public int Invoke(
WSelectQueryBlock selectQueryBlock)
{
aggregateFunctionCount = 0;
if (selectQueryBlock != null)
{
selectQueryBlock.Accept(this);
}
return(aggregateFunctionCount);
}
public override WTableReference ToTableReference()
{
WSelectQueryBlock queryBlock = SubqueryContext.ToSelectQueryBlock();
queryBlock.SelectElements.Clear();
List <WScalarExpression> foldParameters = new List <WScalarExpression> {
SubqueryContext.PivotVariable.ToCompose1()
};
queryBlock.SelectElements.Add(SqlUtil.GetSelectScalarExpr(SqlUtil.GetFunctionCall(GremlinKeyword.func.Fold, foldParameters), GremlinKeyword.TableDefaultColumnName));
return(SqlUtil.GetDerivedTable(queryBlock, GetVariableName()));
}
private WSelectQueryBlock GetSelectQueryBlock(GremlinToSqlContext context)
{
if (context == null)
{
var queryBlock = new WSelectQueryBlock();
queryBlock.SelectElements.Add(SqlUtil.GetSelectScalarExpr(InputVariable.GetDefaultProjection().ToScalarExpression()));
return(queryBlock);
}
else
{
return(context.ToSelectQueryBlock());
}
}
public override WTableReference ToTableReference()
{
List <WScalarExpression> parameters = new List <WScalarExpression>();
for (var i = 0; i < ProjectKeys.Count; i++)
{
WSelectQueryBlock selectBlock = ProjectContextList[i % ProjectContextList.Count].ToSelectQueryBlock(true);
parameters.Add(SqlUtil.GetScalarSubquery(selectBlock));
parameters.Add(SqlUtil.GetValueExpr(ProjectKeys[i]));
}
var tableRef = SqlUtil.GetFunctionTableReference(GremlinKeyword.func.Project, parameters, GetVariableName());
return(SqlUtil.GetCrossApplyTableReference(tableRef));
}
public override WTableReference ToTableReference()
{
List <WScalarExpression> parameters = new List <WScalarExpression>();
//TODO: refactor
WSelectQueryBlock selectQueryBlock = ProjectContext.ToSelectQueryBlock();
selectQueryBlock.SelectElements.Clear();
selectQueryBlock.SelectElements.Add(SqlUtil.GetSelectScalarExpr(ProjectContext.PivotVariable.ToCompose1(), GremlinKeyword.TableDefaultColumnName));
parameters.Add(SqlUtil.GetScalarSubquery(selectQueryBlock));
parameters.Add(SqlUtil.GetValueExpr(SideEffectKey));
var secondTableRef = SqlUtil.GetFunctionTableReference(GremlinKeyword.func.Store, parameters, this, GetVariableName());
return(SqlUtil.GetCrossApplyTableReference(null, secondTableRef));
}
public WDeleteEdgeSpecification(WSelectQueryBlock deleteSpec)
{
SelectDeleteExpr = deleteSpec;
//FromClause = new WFromClause
//{
// TableReferences = new List<WTableReference>
// {
// new WQueryDerivedTable
// {
// QueryExpr = deleteSpec
// }
// }
//};
EdgeColumn = deleteSpec.MatchClause.Paths[0].PathEdgeList[0].Item2;
}
public WDeleteEdgeSpecification(WSelectQueryBlock deleteSpec)
{
SelectDeleteExpr = deleteSpec;
//FromClause = new WFromClause
//{
// TableReferences = new List<WTableReference>
// {
// new WQueryDerivedTable
// {
// QueryExpr = deleteSpec
// }
// }
//};
EdgeColumn = deleteSpec.MatchClause.Paths[0].PathEdgeList[0].Item2;
}
public override WTableReference ToTableReference()
{
WSelectQueryBlock queryBlock = SubqueryContext.ToSelectQueryBlock();
queryBlock.SelectElements.Clear();
if (SubqueryContext.PivotVariable.ProjectedProperties.Count == 0)
{
SubqueryContext.PivotVariable.ProjectedProperties.Add(GetProjectKey());
}
List <WScalarExpression> foldParameters = new List <WScalarExpression> {
SubqueryContext.PivotVariable.ToCompose1()
};
queryBlock.SelectElements.Add(SqlUtil.GetSelectScalarExpr(SqlUtil.GetFunctionCall(GremlinKeyword.func.Fold, foldParameters), GremlinKeyword.ScalarValue));
return(SqlUtil.GetDerivedTable(queryBlock, GetVariableName()));
}
public override WTableReference ToTableReference()
{
List <WScalarExpression> parameters = new List <WScalarExpression>();
parameters.Add(SqlUtil.GetValueExpr(this.SideEffectKey));
WSelectQueryBlock groupBlock = this.GroupByContext.ToSelectQueryBlock(true);
parameters.Add(SqlUtil.GetScalarSubquery(groupBlock));
WSelectQueryBlock projectBlock = this.ProjectByContext.ToSelectQueryBlock(true);
parameters.Add(SqlUtil.GetScalarSubquery(projectBlock));
var tableRef = SqlUtil.GetFunctionTableReference(GremlinKeyword.func.Group, parameters, GetVariableName());
((WGroupTableReference)tableRef).IsProjectingACollection = this.IsProjectingACollection;
return(SqlUtil.GetCrossApplyTableReference(tableRef));
}
public override WTableReference ToTableReference()
{
List <WScalarExpression> parameters = new List <WScalarExpression>();
List <WSelectQueryBlock> queryBlocks = new List <WSelectQueryBlock>();
//Must toSelectQueryBlock before toCompose1 of variableList in order to populate needed columns
foreach (var byContext in ByContexts)
{
//TODO: select compose1
WSelectQueryBlock queryBlock = byContext.ToSelectQueryBlock();
queryBlock.SelectElements.Clear();
queryBlock.SelectElements.Add(SqlUtil.GetSelectScalarExpr(byContext.PivotVariable.ToCompose1(), GremlinKeyword.TableDefaultColumnName));
queryBlocks.Add(queryBlock);
}
if (IsInRepeatContext)
{
//Must add as the first parameter
parameters.Add(SqlUtil.GetColumnReferenceExpr(GremlinKeyword.RepeatInitalTableName, GremlinKeyword.Path));
}
foreach (var path in PathList)
{
if (path.AttachedVariable != null)
{
parameters.Add(SqlUtil.GetColumnReferenceExpr(path.AttachedVariable.GetVariableName(), GremlinKeyword.Path));
}
else
{
parameters.Add(path.StepVariable.First().ToCompose1());
}
}
foreach (var block in queryBlocks)
{
parameters.Add(SqlUtil.GetScalarSubquery(block));
}
var tableRef = SqlUtil.GetFunctionTableReference(GremlinKeyword.func.Path2, parameters, GetVariableName());
return(SqlUtil.GetCrossApplyTableReference(tableRef));
}
public override WTableReference ToTableReference()
{
List <WScalarExpression> parameters = new List <WScalarExpression>();
foreach (var row in rows)
{
if (row is string || row is int)
{
var queryBlock = new WSelectQueryBlock();
queryBlock.SelectElements.Add(SqlUtil.GetSelectScalarExpr(SqlUtil.GetValueExpr(row), "_value"));
parameters.Add(SqlUtil.GetScalarSubquery(queryBlock));
}
else
{
throw new NotImplementedException();
}
}
var secondTableRef = SqlUtil.GetFunctionTableReference(GremlinKeyword.func.Inject, parameters, this, GetVariableName());
return(SqlUtil.GetCrossApplyTableReference(null, secondTableRef));
}
public override WTableReference ToTableReference()
{
WSelectQueryBlock firstQueryExpr = new WSelectQueryBlock();
foreach (var projectProperty in ProjectedProperties)
{
if (projectProperty == GremlinKeyword.TableDefaultColumnName)
{
firstQueryExpr.SelectElements.Add(SqlUtil.GetSelectScalarExpr(InputVariable.DefaultProjection().ToScalarExpression(),
GremlinKeyword.TableDefaultColumnName));
}
else
if (InputVariable.ProjectedProperties.Contains(projectProperty))
{
firstQueryExpr.SelectElements.Add(
SqlUtil.GetSelectScalarExpr(
InputVariable.GetVariableProperty(projectProperty).ToScalarExpression(), projectProperty));
}
else
{
firstQueryExpr.SelectElements.Add(
SqlUtil.GetSelectScalarExpr(SqlUtil.GetValueExpr(null), projectProperty));
}
}
if (OptionalContext.IsPopulateGremlinPath)
{
firstQueryExpr.SelectElements.Add(SqlUtil.GetSelectScalarExpr(SqlUtil.GetValueExpr(null), GremlinKeyword.Path));
}
WSelectQueryBlock secondQueryExpr = OptionalContext.ToSelectQueryBlock(ProjectedProperties);
var WBinaryQueryExpression = SqlUtil.GetBinaryQueryExpr(firstQueryExpr, secondQueryExpr);
List <WScalarExpression> parameters = new List <WScalarExpression>();
parameters.Add(SqlUtil.GetScalarSubquery(WBinaryQueryExpression));
var tableRef = SqlUtil.GetFunctionTableReference(GremlinKeyword.func.Optional, parameters, GetVariableName());
return(SqlUtil.GetCrossApplyTableReference(tableRef));
}
public override WTableReference ToTableReference()
{
WSelectQueryBlock queryBlock = SubqueryContext.ToSelectQueryBlock();
queryBlock.SelectElements.Clear();
List <WValueExpression> columnListExpr = new List <WValueExpression>();
foreach (var projectProperty in ProjectedProperties)
{
columnListExpr.Add(SqlUtil.GetValueExpr(projectProperty));
}
List <WScalarExpression> capParameters = new List <WScalarExpression>();
foreach (var sideEffectKey in SideEffectKeys)
{
capParameters.Add(new WColumnNameList(columnListExpr));
capParameters.Add(SqlUtil.GetValueExpr(sideEffectKey));
}
queryBlock.SelectElements.Add(SqlUtil.GetSelectScalarExpr(SqlUtil.GetFunctionCall(GremlinKeyword.func.Cap, capParameters), GremlinKeyword.ScalarValue));
return(SqlUtil.GetDerivedTable(queryBlock, GetVariableName()));
}
internal void Split(out WSelectQueryBlock contextSelect, out WSelectQueryBlock repeatSelectQuery)
{
WScalarSubquery repeatInput = Parameters[0] as WScalarSubquery;
if (repeatInput == null)
{
throw new SyntaxErrorException("The input of a repeat table reference must be a scalar subquery.");
}
WBinaryQueryExpression binaryQuery = repeatInput.SubQueryExpr as WBinaryQueryExpression;
if (binaryQuery == null || binaryQuery.BinaryQueryExprType != BinaryQueryExpressionType.Union || !binaryQuery.All)
{
throw new SyntaxErrorException("The input of a repeat table reference must be a UNION ALL binary query expression.");
}
contextSelect = binaryQuery.FirstQueryExpr as WSelectQueryBlock;
repeatSelectQuery = binaryQuery.SecondQueryExpr as WSelectQueryBlock;
if (contextSelect == null || repeatSelectQuery == null)
{
throw new SyntaxErrorException("The input of a repeat table reference must be a UNION ALL binary query and the two sub-queries must be a select query block.");
}
}
public override WTableReference ToTableReference()
{
List <WScalarExpression> parameters = new List <WScalarExpression>();
if (this.UnionContextList.Count == 0)
{
parameters.AddRange(this.ProjectedProperties.Select(SqlUtil.GetValueExpr));
}
else
{
foreach (GremlinToSqlContext context in this.UnionContextList)
{
WSelectQueryBlock selectQueryBlock = context.ToSelectQueryBlock();
Dictionary <string, WSelectElement> projectionMap = new Dictionary <string, WSelectElement>();
WSelectElement value = selectQueryBlock.SelectElements[0];
foreach (WSelectElement selectElement in selectQueryBlock.SelectElements)
{
projectionMap[(selectElement as WSelectScalarExpression).ColumnName] = selectElement;
}
selectQueryBlock.SelectElements.Clear();
selectQueryBlock.SelectElements.Add(SqlUtil.GetSelectScalarExpr((value as WSelectScalarExpression).SelectExpr, this.DefaultProperty()));
foreach (string property in this.ProjectedProperties)
{
selectQueryBlock.SelectElements.Add(
projectionMap.TryGetValue(property, out value)
? value : SqlUtil.GetSelectScalarExpr(SqlUtil.GetValueExpr(null), property));
}
parameters.Add(SqlUtil.GetScalarSubquery(selectQueryBlock));
}
}
var tableRef = SqlUtil.GetFunctionTableReference(GremlinKeyword.func.Union, parameters, GetVariableName());
return(SqlUtil.GetCrossApplyTableReference(tableRef));
}
public override void Visit(WSelectQueryBlock node)
{
UpdateMapping(node);
}
/// <summary>
/// Estimate number of rows of node table in graph.
/// </summary>
/// <param name="graph">Constructed node graph</param>
private void EstimateRows(WSelectQueryBlock query, MatchGraph graph)
{
var declareParameter = "";
if (_variables != null)
{
foreach (var parameter in _variables)
{
declareParameter += "DECLARE " + parameter.VariableName.Value + " " +
TsqlFragmentToString.DataType(parameter.DataType) + "\r\n";
}
}
var estimator = new TableSizeEstimator(Conn);
bool first = true;
var fromQuerySb = new StringBuilder(1024);
foreach (var subGraph in graph.ConnectedSubGraphs)
{
foreach (var node in subGraph.Nodes)
{
if (first)
first = false;
else
fromQuerySb.Append(", ");
var currentNode = node.Value;
fromQuerySb.AppendFormat("{0} AS [{1}] WITH (ForceScan)", currentNode.TableObjectName,
currentNode.NodeAlias);
}
}
// Attach proper parts of the where clause into the Estimiation Query
var columnTableMapping = _context.GetColumnTableMapping(_columnsOfNodeTables);
var attachWhereClauseVisiter = new AttachNodeEdgePredictesVisitor();
var nodeEstimationWhereClause = attachWhereClauseVisiter.Invoke(query.WhereClause, graph, columnTableMapping);
string nodeEstimationQuery = string.Format("{0}\r\n SELECT * FROM {1}\r\n", declareParameter,
fromQuerySb);
if (nodeEstimationWhereClause.SearchCondition != null)
nodeEstimationQuery += nodeEstimationWhereClause.ToString();
var estimateRows = estimator.GetQueryTableEstimatedRows(nodeEstimationQuery);
foreach (var subGraph in graph.ConnectedSubGraphs)
{
// Update Row Estimation for nodes
foreach (var node in subGraph.Nodes)
{
var currentNode = node.Value;
currentNode.EstimatedRows = estimateRows[node.Key];
var tableSchema = currentNode.TableObjectName.SchemaIdentifier.Value;
var tableName = currentNode.TableObjectName.BaseIdentifier.Value;
currentNode.TableRowCount = estimator.GetTableRowCount(tableSchema, tableName);
}
}
// Attach predicates to nodes and edges
var attachPredicateVisitor = new AttachWhereClauseVisitor();
attachPredicateVisitor.Invoke(query.WhereClause, graph, columnTableMapping);
}
public override WTableReference ToTableReference()
{
Dictionary <GremlinVariableProperty, string> map = new Dictionary <GremlinVariableProperty, string>();
Dictionary <GremlinVariableProperty, string> map2 = new Dictionary <GremlinVariableProperty, string>();
Dictionary <GremlinVariableProperty, string> map3 = new Dictionary <GremlinVariableProperty, string>();
Dictionary <GremlinVariableProperty, string> map4 = new Dictionary <GremlinVariableProperty, string>();
WRepeatConditionExpression conditionExpr = GetRepeatConditionExpression();
List <WSelectScalarExpression> inputSelectList = GetInputSelectList(ref map);
List <WSelectScalarExpression> outerSelectList = GetOuterSelectList(ref map);
List <WSelectScalarExpression> terminateSelectList = GetConditionSelectList(ref map2);
List <WSelectScalarExpression> repeatPathOuterList = GetRepeatPathOuterVariableList(ref map3);
List <WSelectScalarExpression> conditionPathOuterList = GetConditionPathOuterVariableList(ref map4);
WSelectQueryBlock selectQueryBlock = RepeatContext.ToSelectQueryBlock();
selectQueryBlock.SelectElements.Clear();
foreach (var selectElement in inputSelectList)
{
selectQueryBlock.SelectElements.Add(selectElement);
}
foreach (var selectElement in outerSelectList)
{
selectQueryBlock.SelectElements.Add(selectElement);
}
foreach (var selectElement in terminateSelectList)
{
selectQueryBlock.SelectElements.Add(selectElement);
}
foreach (var selectElement in repeatPathOuterList)
{
selectQueryBlock.SelectElements.Add(selectElement);
}
foreach (var selectElement in conditionPathOuterList)
{
selectQueryBlock.SelectElements.Add(selectElement);
}
WSelectQueryBlock firstQueryExpr = new WSelectQueryBlock();
foreach (var item in map)
{
firstQueryExpr.SelectElements.Add(SqlUtil.GetSelectScalarExpr(item.Key.ToScalarExpression(), item.Value));
}
foreach (var item in map2)
{
firstQueryExpr.SelectElements.Add(SqlUtil.GetSelectScalarExpr(SqlUtil.GetValueExpr(null), item.Value));
}
foreach (var item in map3)
{
firstQueryExpr.SelectElements.Add(SqlUtil.GetSelectScalarExpr(item.Key.ToScalarExpression(), item.Value));
}
foreach (var item in map4)
{
firstQueryExpr.SelectElements.Add(SqlUtil.GetSelectScalarExpr(item.Key.ToScalarExpression(), item.Value));
}
//firstQueryExpr.SelectElements.Add(SqlUtil.GetSelectScalarExpr(FirstVariable.DefaultProjection().ToScalarExpression(), GremlinKeyword.TableDefaultColumnName));
//selectQueryBlock.SelectElements.Add(SqlUtil.GetSelectScalarExpr(RepeatContext.PivotVariable.DefaultProjection().ToScalarExpression(), GremlinKeyword.TableDefaultColumnName));
foreach (var property in ProjectedProperties)
{
if (InputVariable.ProjectedProperties.Contains(property))
{
firstQueryExpr.SelectElements.Add(
SqlUtil.GetSelectScalarExpr(
InputVariable.GetVariableProperty(property).ToScalarExpression(), property));
}
else
{
firstQueryExpr.SelectElements.Add(
SqlUtil.GetSelectScalarExpr(SqlUtil.GetValueExpr(null), property));
}
if (RepeatContext.PivotVariable.ProjectedProperties.Contains(property))
{
selectQueryBlock.SelectElements.Add(
SqlUtil.GetSelectScalarExpr(
RepeatContext.PivotVariable.GetVariableProperty(property).ToScalarExpression(), property));
}
else
{
selectQueryBlock.SelectElements.Add(
SqlUtil.GetSelectScalarExpr(SqlUtil.GetValueExpr(null), property));
}
}
if (SelectedVariableList.Count != 0)
{
foreach (var selectedVariableTuple in SelectedVariableList)
{
var columnName = selectedVariableTuple.Item1;
var selectedVariable = selectedVariableTuple.Item2;
firstQueryExpr.SelectElements.Add(SqlUtil.GetSelectScalarExpr(SqlUtil.GetValueExpr(null), columnName));
List <WScalarExpression> compose2Paramters = new List <WScalarExpression>();
compose2Paramters.Add(selectedVariable.RealVariable.ToCompose1());
compose2Paramters.Add(SqlUtil.GetColumnReferenceExpr("R", columnName));
WFunctionCall compose2 = SqlUtil.GetFunctionCall(GremlinKeyword.func.Compose2, compose2Paramters);
selectQueryBlock.SelectElements.Add(SqlUtil.GetSelectScalarExpr(compose2, columnName));
}
}
if (RepeatContext.IsPopulateGremlinPath)
{
var columnName = GremlinKeyword.Path;
var pathVariable = RepeatContext.CurrentContextPath;
firstQueryExpr.SelectElements.Add(SqlUtil.GetSelectScalarExpr(SqlUtil.GetValueExpr(null), columnName));
selectQueryBlock.SelectElements.Add(SqlUtil.GetSelectScalarExpr(pathVariable.DefaultProjection().ToScalarExpression(), columnName));
}
var WBinaryQueryExpression = SqlUtil.GetBinaryQueryExpr(firstQueryExpr, selectQueryBlock);
ModifyColumnNameVisitor newVisitor = new ModifyColumnNameVisitor();
newVisitor.Invoke(selectQueryBlock, map);
newVisitor.Invoke(conditionExpr, map2);
newVisitor.Invoke(selectQueryBlock, map3);
newVisitor.Invoke(conditionExpr, map4);
List <WScalarExpression> repeatParameters = new List <WScalarExpression>();
repeatParameters.Add(SqlUtil.GetScalarSubquery(WBinaryQueryExpression));
repeatParameters.Add(conditionExpr);
var secondTableRef = SqlUtil.GetFunctionTableReference(GremlinKeyword.func.Repeat, repeatParameters, this, GetVariableName());
return(SqlUtil.GetCrossApplyTableReference(null, secondTableRef));
}
/// <summary>
/// Check validity of the match clause
/// </summary>
/// <param name="node"></param>
private void CheckValidity(WSelectQueryBlock node)
{
if (node.MatchClause == null)
return;
if (node.MatchClause.Paths.All(
path => path.PathNodeList.All(
part => _context.CheckTable(part.Item1.BaseIdentifier.Value) &&
IsNodeTable(_context[part.Item1.BaseIdentifier.Value])
)
))
{
foreach (var path in node.MatchClause.Paths)
{
var index = 0;
for (var count = path.PathNodeList.Count; index < count; ++index)
{
var pathNode = path.PathNodeList[index];
var table = _context[pathNode.Item1.BaseIdentifier.Value] as WNamedTableReference;
var edge =
pathNode.Item2.MultiPartIdentifier.Identifiers.Last().Value.ToLower();
var nodeTableKey = WNamedTableReference.SchemaNameToTuple(table.TableObjectName);
if (_columnsOfNodeTables[nodeTableKey].ContainsKey(edge))
{
if (
_columnsOfNodeTables.Keys.Contains(
new Tuple<string, string>(nodeTableKey.Item1.ToLower(CultureInfo.CurrentCulture),
_columnsOfNodeTables[nodeTableKey][edge].Reference)))
{
var nextNode = index != count - 1
? path.PathNodeList[index + 1].Item1
: path.Tail;
var getNextTable = _context[nextNode.BaseIdentifier.Value];
if (!IsNodeTable(getNextTable))
throw new GraphViewException("Node table expected in MATCH clause");
var nextTable = getNextTable as WNamedTableReference;
if (nextTable == null ||
!String.Equals(nextTable.TableObjectName.BaseIdentifier.Value,
_columnsOfNodeTables[nodeTableKey][edge].Reference,
StringComparison.CurrentCultureIgnoreCase))
{
throw new GraphViewException(String.Format(CultureInfo.CurrentCulture,
"Wrong Reference Table {0}", nextNode.BaseIdentifier.Value));
}
}
else
{
throw new GraphViewException(String.Format(CultureInfo.CurrentCulture,
"Node Table Referenced by the Edge {0} not exists", edge));
}
}
else
{
throw new GraphViewException(String.Format(CultureInfo.CurrentCulture,
"Edge Column {0} not exists in the Node Table", edge));
}
}
}
}
else
{
throw new GraphViewException("Node table expected in MATCH clause");
}
}
public void Invoke(WSelectQueryBlock node)
{
node.Accept(this);
}
public override void Visit(WSelectQueryBlock node)
{
base.Visit(node);
var flag = false;
for (var i = 0; i < MatchList.Count; ++i)
{
if (MatchFlag[i])
continue;
var nextToken = node.LastTokenIndex + 1;
while (nextToken < Tokens.Count && Tokens[nextToken].TokenType == TSqlTokenType.WhiteSpace)
nextToken++;
var insideBlock = (node.FirstTokenIndex < MatchList[i].FirstTokenIndex &&
(node.LastTokenIndex > MatchList[i].LastTokenIndex ||
nextToken == MatchList[i].FirstTokenIndex));
if (!insideBlock)
continue;
nextToken = node.FromClause.LastTokenIndex + 1;
while (nextToken < Tokens.Count && Tokens[nextToken].TokenType == TSqlTokenType.WhiteSpace)
nextToken++;
// match clause should exactly follow FROM clause
if (node.FromClause.TableReferences == null ||
nextToken != MatchList[i].FirstTokenIndex)
{
var token = Tokens[nextToken];
_errors.Add(new ParseError(0, token.Offset, token.Line, token.Column,
"MATCH clause should exactly follow FROM clause"));
}
// if a where/top row filter/group by/having clause exists, it should be followed by a match clause
if (node.WhereClause.SearchCondition != null &&
node.WhereClause.FirstTokenIndex < MatchList[i].LastTokenIndex)
{
var token = Tokens[nextToken];
_errors.Add(new ParseError(0, token.Offset, token.Line, token.Column,
"WHERE clause should be followed by a MATCH clause"));
}
if (node.TopRowFilter != null &&
node.TopRowFilter.FirstTokenIndex < MatchList[i].LastTokenIndex)
{
var token = Tokens[nextToken];
_errors.Add(new ParseError(0, token.Offset, token.Line, token.Column,
"Top row filter should be followed by a MATCH clause"));
}
if (node.GroupByClause != null &&
node.GroupByClause.FirstTokenIndex < MatchList[i].LastTokenIndex)
{
var token = Tokens[nextToken];
_errors.Add(new ParseError(0, token.Offset, token.Line, token.Column,
"GROUP BY clause should be followed by a MATCH clause"));
}
if (node.HavingClause != null &&
node.HavingClause.FirstTokenIndex < MatchList[i].LastTokenIndex)
{
var token = Tokens[nextToken];
_errors.Add(new ParseError(0, token.Offset, token.Line, token.Column,
"HAVING clause should be followed by a MATCH clause"));
}
if (flag)
{
var token = Tokens[nextToken];
_errors.Add(new ParseError(0, token.Offset, token.Line, token.Column,
"Mutiple MATCH clauses in same query block"));
}
if (_errors.Count > 0)
return;
if (node.LastTokenIndex < MatchList[i].FirstTokenIndex)
{
node.LastTokenIndex = MatchList[i].LastTokenIndex;
}
flag = true;
if (node.MatchClause != null && node.MatchClause.Paths != null && node.MatchClause.Paths.Any())
{
foreach (var path in MatchList[i].Paths)
{
node.MatchClause.Paths.Add(path);
}
}
else
{
node.MatchClause = MatchList[i];
}
MatchFlag[i] = true;
}
}
/// <summary>
/// Constructs the graph pattern specified by the MATCH clause.
/// The graph pattern may consist of multiple fully-connected sub-graphs.
/// </summary>
/// <param name="query">The SELECT query block</param>
/// <returns>A graph object contains all the connected componeents</returns>
private MatchGraph ConstructGraph(WSelectQueryBlock query)
{
if (query == null || query.MatchClause == null)
return null;
var unionFind = new UnionFind();
var edgeColumnToAliasesDict = new Dictionary<string, List<string>>(StringComparer.OrdinalIgnoreCase);
var pathDictionary = new Dictionary<string, MatchPath>(StringComparer.OrdinalIgnoreCase);
var matchClause = query.MatchClause;
var nodes = new Dictionary<string, MatchNode>(StringComparer.OrdinalIgnoreCase);
var connectedSubGraphs = new List<ConnectedComponent>();
var subGrpahMap = new Dictionary<string, ConnectedComponent>(StringComparer.OrdinalIgnoreCase);
var parent = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
unionFind.Parent = parent;
// Constructs the graph pattern specified by the path expressions in the MATCH clause
foreach (var path in matchClause.Paths)
{
var index = 0;
MatchEdge preEdge = null;
for (var count = path.PathEdgeList.Count; index < count; ++index)
{
var currentNodeTableRef = path.PathEdgeList[index].Item1;
var currentEdgeColumnRef = path.PathEdgeList[index].Item2;
var currentNodeExposedName = currentNodeTableRef.BaseIdentifier.Value;
var nextNodeTableRef = index != count - 1
? path.PathEdgeList[index + 1].Item1
: path.Tail;
var nextNodeExposedName = nextNodeTableRef.BaseIdentifier.Value;
var patternNode = nodes.GetOrCreate(currentNodeExposedName);
if (patternNode.NodeAlias == null)
{
patternNode.NodeAlias = currentNodeExposedName;
patternNode.Neighbors = new List<MatchEdge>();
patternNode.External = false;
var nodeTable = _context[currentNodeExposedName] as WNamedTableReference;
if (nodeTable != null)
{
patternNode.NodeTableObjectName = nodeTable.TableObjectName;
if (patternNode.NodeTableObjectName.SchemaIdentifier == null)
patternNode.NodeTableObjectName.Identifiers.Insert(0, new Identifier {Value = "dbo"});
}
}
string edgeAlias = currentEdgeColumnRef.Alias;
if (edgeAlias == null)
{
var currentEdgeName = currentEdgeColumnRef.MultiPartIdentifier.Identifiers.Last().Value;
edgeAlias = string.Format("{0}_{1}_{2}", currentNodeExposedName, currentEdgeName,
nextNodeExposedName);
if (edgeColumnToAliasesDict.ContainsKey(currentEdgeName))
{
edgeColumnToAliasesDict[currentEdgeName].Add(edgeAlias);
}
else
{
edgeColumnToAliasesDict.Add(currentEdgeName, new List<string> { edgeAlias });
}
}
Identifier edgeIdentifier = currentEdgeColumnRef.MultiPartIdentifier.Identifiers.Last();
string schema = patternNode.NodeTableObjectName.SchemaIdentifier.Value.ToLower();
string nodeTableName = patternNode.NodeTableObjectName.BaseIdentifier.Value;
string bindTableName =
_context.EdgeNodeBinding[
new Tuple<string, string>(nodeTableName.ToLower(), edgeIdentifier.Value.ToLower())].ToLower();
MatchEdge edge;
if (currentEdgeColumnRef.MinLength == 1 && currentEdgeColumnRef.MaxLength == 1)
{
edge = new MatchEdge
{
SourceNode = patternNode,
EdgeColumn = currentEdgeColumnRef,
EdgeAlias = edgeAlias,
BindNodeTableObjName =
new WSchemaObjectName(
new Identifier {Value = schema},
new Identifier {Value = bindTableName}
),
};
_context.AddEdgeReference(edge);
}
else
{
MatchPath matchPath = new MatchPath
{
SourceNode = patternNode,
EdgeColumn = currentEdgeColumnRef,
EdgeAlias = edgeAlias,
BindNodeTableObjName =
new WSchemaObjectName(
new Identifier {Value = schema},
new Identifier {Value = bindTableName}
),
MinLength = currentEdgeColumnRef.MinLength,
MaxLength = currentEdgeColumnRef.MaxLength,
ReferencePathInfo = false,
AttributeValueDict = currentEdgeColumnRef.AttributeValueDict
};
_context.AddEdgeReference(matchPath);
pathDictionary[edgeAlias] = matchPath;
edge = matchPath;
}
if (preEdge != null)
{
preEdge.SinkNode = patternNode;
}
preEdge = edge;
if (!parent.ContainsKey(currentNodeExposedName))
parent[currentNodeExposedName] = currentNodeExposedName;
if (!parent.ContainsKey(nextNodeExposedName))
parent[nextNodeExposedName] = nextNodeExposedName;
unionFind.Union(currentNodeExposedName, nextNodeExposedName);
patternNode.Neighbors.Add(edge);
}
var tailExposedName = path.Tail.BaseIdentifier.Value;
var tailNode = nodes.GetOrCreate(tailExposedName);
if (tailNode.NodeAlias == null)
{
tailNode.NodeAlias = tailExposedName;
tailNode.Neighbors = new List<MatchEdge>();
var nodeTable = _context[tailExposedName] as WNamedTableReference;
if (nodeTable != null)
{
tailNode.NodeTableObjectName = nodeTable.TableObjectName;
if (tailNode.NodeTableObjectName.SchemaIdentifier == null)
tailNode.NodeTableObjectName.Identifiers.Insert(0, new Identifier {Value = "dbo"});
}
}
if (preEdge != null)
preEdge.SinkNode = tailNode;
}
// Puts nodes into subgraphs
foreach (var node in nodes)
{
string root = unionFind.Find(node.Key);
if (!subGrpahMap.ContainsKey(root))
{
var subGraph = new ConnectedComponent();
subGraph.Nodes[node.Key] = node.Value;
foreach (var edge in node.Value.Neighbors)
{
subGraph.Edges[edge.EdgeAlias] = edge;
}
subGrpahMap[root] = subGraph;
connectedSubGraphs.Add(subGraph);
subGraph.IsTailNode[node.Value] = false;
}
else
{
var subGraph = subGrpahMap[root];
subGraph.Nodes[node.Key] = node.Value;
foreach (var edge in node.Value.Neighbors)
{
subGraph.Edges[edge.EdgeAlias] = edge;
}
subGraph.IsTailNode[node.Value] = false;
}
}
var graph = new MatchGraph
{
ConnectedSubGraphs = connectedSubGraphs,
};
unionFind.Parent = null;
// When an edge in the MATCH clause is not associated with an alias,
// assigns to it a default alias: sourceAlias_EdgeColumnName_sinkAlias.
// Also rewrites edge attributes anywhere in the query that can be bound to this default alias.
var replaceTableRefVisitor = new ReplaceEdgeReferenceVisitor();
replaceTableRefVisitor.Invoke(query, edgeColumnToAliasesDict);
// Rematerializes node tables in the MATCH clause which are defined in the upper-level context
// and join them with the upper-level table references.
RematerilizeExtrenalNodeTableReference(query, nodes);
// Transforms the path reference in the SELECT elements into a
// scalar function to display path information.
TransformPathInfoDisplaySelectElement(query, pathDictionary);
return graph;
}
private void TranslateEdgeDelete(WDeleteEdgeSpecification node, List<WSqlStatement> res)
{
const string deleteEdgeTableName = "GraphView_DeleteEdgeInternalTable";
string deleteEdgeTempTable = "DeleteTmp_" + Path.GetRandomFileName().Replace(".", "").Substring(0, 8);
// Wraps the select statement in a common table expression
WTableReference sinkTable, sourceTable;
var deleteCommonTableExpr = ConstructDeleteEdgeSelect(node.SelectDeleteExpr,
node.EdgeColumn.Alias, deleteEdgeTempTable,
out sinkTable, out sourceTable);
var sourceNameTable = sourceTable as WNamedTableReference;
if (sourceNameTable == null)
throw new GraphViewException("Source table of DELETE EDGE statement should be a named table reference.");
var sinkNameTable = sinkTable as WNamedTableReference;
if (sinkNameTable == null)
throw new GraphViewException("Sink table of DELETE EDGE statement should be a named table reference.");
// Get edge select query and reversed edge select query
WSelectQueryBlock edgeSelectQuery = new WSelectQueryBlock
{
SelectElements = new List<WSelectElement>
{
new WSelectScalarExpression
{
SelectExpr = new WColumnReferenceExpression
{
MultiPartIdentifier = new WMultiPartIdentifier(new Identifier {Value = "src"})
},
ColumnName = "source"
},
new WSelectScalarExpression
{
SelectExpr = new WFunctionCall
{
CallTarget = new WMultiPartIdentifierCallTarget
{
Identifiers = new WMultiPartIdentifier(new Identifier {Value = "dbo"})
},
FunctionName = new Identifier {Value = GraphViewConnection.GraphViewUdfAssemblyName + "EdgeIdEncoder"},
Parameters = new List<WScalarExpression>
{
new WColumnReferenceExpression
{
MultiPartIdentifier = new WMultiPartIdentifier(new Identifier {Value = "edgeid"})
},
},
},
ColumnName = "binary1"
},
new WSelectScalarExpression
{
SelectExpr = new WFunctionCall
{
FunctionName = new Identifier{Value = "COUNT"},
Parameters = new List<WScalarExpression>
{
new WColumnReferenceExpression
{
MultiPartIdentifier = new WMultiPartIdentifier(new Identifier {Value = "sink"})
},
},
},
ColumnName = "sinkCnt"
}
},
FromClause = new WFromClause
{
TableReferences = new List<WTableReference>
{
new WSpecialNamedTableReference
{
TableObjectName = new WSchemaObjectName(new Identifier{Value = deleteEdgeTempTable })
}
}
},
GroupByClause = new WGroupByClause
{
GroupingSpecifications = new List<WGroupingSpecification>
{
new WExpressionGroupingSpec
{
Expression = new WValueExpression("src",false)
}
}
}
};
WSelectQueryBlock reversedEdgeSelectQuery = new WSelectQueryBlock
{
SelectElements = new List<WSelectElement>
{
new WSelectScalarExpression
{
SelectExpr = new WColumnReferenceExpression
{
MultiPartIdentifier = new WMultiPartIdentifier(new Identifier {Value = "sink"})
},
ColumnName = "source"
},
new WSelectScalarExpression
{
SelectExpr = new WFunctionCall
{
FunctionName =
new Identifier
{
Value = "COUNT"
},
Parameters = new List<WScalarExpression>
{
new WColumnReferenceExpression
{
MultiPartIdentifier = new WMultiPartIdentifier(new Identifier {Value = "src"})
},
}
},
ColumnName = "srcCnt"
},
},
FromClause = edgeSelectQuery.FromClause,
GroupByClause = new WGroupByClause
{
GroupingSpecifications = new List<WGroupingSpecification>
{
new WExpressionGroupingSpec
{
Expression = new WValueExpression("sink", false)
}
}
}
};
//Check src & sink
string sourceTableName = sourceNameTable.TableObjectName.ToString();
string sinkTableName = sinkNameTable.TableObjectName.ToString();
int compare = string.CompareOrdinal(sourceTableName, sinkTableName);
WSetClause[] setClauses = new WSetClause[]
{
new WFunctionCallSetClause()
{
MutatorFuction = new WFunctionCall
{
CallTarget = new WMultiPartIdentifierCallTarget()
{
Identifiers =
new WMultiPartIdentifier(new Identifier
{
Value = node.EdgeColumn.MultiPartIdentifier.Identifiers.Last().Value + "DeleteCol"
})
},
FunctionName = new Identifier {Value = "WRITE"},
Parameters = new WScalarExpression[]
{
new WColumnReferenceExpression
{
MultiPartIdentifier = new WMultiPartIdentifier(
new Identifier {Value = deleteEdgeTableName},
new Identifier {Value = "binary1"})
},
new WValueExpression("null", false),
new WValueExpression("null", false)
}
}
},
new WAssignmentSetClause()
{
AssignmentKind = AssignmentKind.Equals,
Column = new WColumnReferenceExpression
{
MultiPartIdentifier =
new WMultiPartIdentifier(new Identifier
{
Value = "InDegree"
})
},
NewValue = new WBinaryExpression
{
FirstExpr = new WColumnReferenceExpression
{
MultiPartIdentifier =
new WMultiPartIdentifier(new Identifier
{
Value = "InDegree"
})
},
SecondExpr = new WColumnReferenceExpression
{
MultiPartIdentifier = new WMultiPartIdentifier(new Identifier {Value = "srcCnt"})
},
ExpressionType = BinaryExpressionType.Subtract
}
},
new WAssignmentSetClause()
{
AssignmentKind = AssignmentKind.Equals,
Column = new WColumnReferenceExpression
{
MultiPartIdentifier =
new WMultiPartIdentifier(new Identifier
{
Value = node.EdgeColumn.MultiPartIdentifier.Identifiers.Last().Value + "OutDegree"
})
},
NewValue = new WBinaryExpression
{
FirstExpr = new WColumnReferenceExpression
{
MultiPartIdentifier =
new WMultiPartIdentifier(new Identifier
{
Value = node.EdgeColumn.MultiPartIdentifier.Identifiers.Last().Value + "OutDegree"
})
},
SecondExpr = new WColumnReferenceExpression
{
MultiPartIdentifier = new WMultiPartIdentifier(new Identifier {Value = "sinkCnt"})
},
ExpressionType = BinaryExpressionType.Subtract
}
}
};
WWhereClause whereClause = new WWhereClause
{
SearchCondition = new WBooleanComparisonExpression
{
FirstExpr = new WColumnReferenceExpression
{
MultiPartIdentifier = new WMultiPartIdentifier(new Identifier { Value = "GlobalNodeId" })
},
SecondExpr = new WColumnReferenceExpression
{
MultiPartIdentifier = new WMultiPartIdentifier(
new Identifier { Value = deleteEdgeTableName },
new Identifier { Value = "source" }
)
},
ComparisonType = BooleanComparisonType.Equals
}
};
if (compare == 0)
{
res.Add(new WDeclareTableVariable
{
VariableName = new Identifier { Value = "@" + deleteEdgeTempTable},
Definition = new WTableDefinition
{
ColumnDefinitions = new WColumnDefinition[]
{
new WColumnDefinition
{
ColumnIdentifier = new Identifier{Value = "source"},
DataType = new WParameterizedDataTypeReference{Name = new WSchemaObjectName(new Identifier{Value = "bigint"})},
Constraints = new List<WConstraintDefinition>
{
new WUniqueConstraintDefinition
{
Clustered = true,
IsPrimaryKey = true
}
}
},
new WColumnDefinition
{
ColumnIdentifier = new Identifier{Value = "binary1"},
DataType = new WParameterizedDataTypeReference
{
Name = new WSchemaObjectName(new Identifier{Value = "varbinary"}),
Parameters = new List<Literal>{new MaxLiteral{Value = "max"}}
},
},
new WColumnDefinition
{
ColumnIdentifier = new Identifier{Value = "sinkCnt"},
DataType = new WParameterizedDataTypeReference
{
Name = new WSchemaObjectName(new Identifier{Value = "int"}),
},
},
new WColumnDefinition
{
ColumnIdentifier = new Identifier{Value = "srcCnt"},
DataType = new WParameterizedDataTypeReference
{
Name = new WSchemaObjectName(new Identifier{Value = "int"}),
},
},
},
Indexes = new List<WIndexDefinition>(),
TableConstraints = new List<WConstraintDefinition>()
}
});
var tableVar = new WSpecialNamedTableReference
{
TableObjectName = new WSchemaObjectName(new Identifier { Value = "@" + deleteEdgeTempTable })
};
res.Add(deleteCommonTableExpr);
res.Add(new WInsertSpecification
{
Target = tableVar,
InsertSource = new WSelectInsertSource
{
Select = new WSelectQueryBlock
{
SelectElements = new WSelectElement[]
{
new WSelectScalarExpression
{
SelectExpr = new WFunctionCall
{
FunctionName = new Identifier {Value = "ISNULL"},
Parameters = new WScalarExpression[]
{
new WColumnReferenceExpression
{
MultiPartIdentifier =
new WSchemaObjectName(new Identifier[]
{
new Identifier {Value = deleteEdgeTableName + "_1"},
new Identifier {Value = "source"}
}),
},
new WColumnReferenceExpression
{
MultiPartIdentifier =
new WSchemaObjectName(new Identifier[]
{
new Identifier {Value = deleteEdgeTableName + "_2"},
new Identifier {Value = "source"}
}),
},
}
},
ColumnName = "source"
},
new WSelectScalarExpression
{
SelectExpr = new WColumnReferenceExpression
{
MultiPartIdentifier =
new WSchemaObjectName(new Identifier[] {new Identifier {Value = "binary1"}}),
}
},
//new WSelectScalarExpression
//{
// SelectExpr = new WColumnReferenceExpression
// {
// MultiPartIdentifier = new WSchemaObjectName(new Identifier[]{new Identifier{Value = "binary2"}}),
// }
//},
new WSelectScalarExpression
{
SelectExpr = new WFunctionCall
{
FunctionName = new Identifier {Value = "ISNULL"},
Parameters = new WScalarExpression[]
{
new WColumnReferenceExpression
{
MultiPartIdentifier =
new WSchemaObjectName(new Identifier[]
{
new Identifier {Value = deleteEdgeTableName + "_1"},
new Identifier {Value = "sinkCnt"}
}),
},
new WValueExpression
{
Value = "0"
},
}
},
ColumnName = "sinkCnt"
},
new WSelectScalarExpression
{
SelectExpr = new WFunctionCall
{
FunctionName = new Identifier {Value = "ISNULL"},
Parameters = new WScalarExpression[]
{
new WColumnReferenceExpression
{
MultiPartIdentifier =
new WSchemaObjectName(new Identifier[]
{
new Identifier {Value = deleteEdgeTableName + "_2"},
new Identifier {Value = "srcCnt"}
}),
},
new WValueExpression
{
Value = "0"
},
}
},
ColumnName = "srcCnt"
},
},
FromClause = new WFromClause
{
TableReferences = new WTableReference[]
{
new WQualifiedJoin
{
QualifiedJoinType = QualifiedJoinType.FullOuter,
FirstTableRef = new WQueryDerivedTable
{
Alias = new Identifier {Value = deleteEdgeTableName + "_1"},
QueryExpr = edgeSelectQuery
},
SecondTableRef = new WQueryDerivedTable
{
Alias = new Identifier {Value = deleteEdgeTableName + "_2"},
QueryExpr = reversedEdgeSelectQuery
},
JoinCondition = new WBooleanComparisonExpression()
{
ComparisonType = BooleanComparisonType.Equals,
FirstExpr = new WColumnReferenceExpression
{
MultiPartIdentifier =
new WSchemaObjectName(new Identifier[]
{
new Identifier {Value = deleteEdgeTableName + "_1"},
new Identifier {Value = "source"}
}),
},
SecondExpr = new WColumnReferenceExpression
{
MultiPartIdentifier =
new WSchemaObjectName(new Identifier[]
{
new Identifier {Value = deleteEdgeTableName + "_2"},
new Identifier {Value = "source"}
}),
}
}
},
}
}
}
}
});
res.Add(new WUpdateSpecification
{
Target = new WNamedTableReference
{
TableObjectName = sourceNameTable.TableObjectName
},
SetClauses = setClauses,
FromClause = new WFromClause
{
TableReferences = new WTableReference[]
{
new WQueryDerivedTable
{
Alias = new Identifier {Value = deleteEdgeTableName},
QueryExpr = new WSelectQueryBlock
{
SelectElements = new List<WSelectElement>()
{
new WSelectStarExpression()
},
FromClause = new WFromClause
{
TableReferences = new List<WTableReference> {tableVar}
}
}
},
}
},
WhereClause = whereClause,
TopRowFilter = node.TopRowFilter,
});
res.Add(new WSqlUnknownStatement
{
Statement = String.Format("DELETE FROM @{0}", deleteEdgeTempTable)
});
}
else
{
// Declare table variables
res.Add(new WDeclareTableVariable
{
VariableName = new Identifier { Value = "@" + deleteEdgeTempTable + "_1" },
Definition = new WTableDefinition
{
ColumnDefinitions = new WColumnDefinition[]
{
new WColumnDefinition
{
ColumnIdentifier = new Identifier {Value = "source"},
DataType =
new WParameterizedDataTypeReference
{
Name = new WSchemaObjectName(new Identifier {Value = "bigint"})
},
Constraints = new List<WConstraintDefinition>
{
new WUniqueConstraintDefinition
{
Clustered = true,
IsPrimaryKey = true
}
}
},
new WColumnDefinition
{
ColumnIdentifier = new Identifier {Value = "binary1"},
DataType = new WParameterizedDataTypeReference
{
Name = new WSchemaObjectName(new Identifier {Value = "varbinary"}),
Parameters = new List<Literal> {new MaxLiteral {Value = "max"}}
},
},
new WColumnDefinition
{
ColumnIdentifier = new Identifier {Value = "sinkCnt"},
DataType = new WParameterizedDataTypeReference
{
Name = new WSchemaObjectName(new Identifier {Value = "int"}),
},
},
},
Indexes = new List<WIndexDefinition>(),
TableConstraints = new List<WConstraintDefinition>()
}
});
res.Add(new WDeclareTableVariable
{
VariableName = new Identifier { Value = "@" + deleteEdgeTempTable + "_2" },
Definition = new WTableDefinition
{
ColumnDefinitions = new WColumnDefinition[]
{
new WColumnDefinition
{
ColumnIdentifier = new Identifier {Value = "source"},
DataType =
new WParameterizedDataTypeReference
{
Name = new WSchemaObjectName(new Identifier {Value = "bigint"})
},
Constraints = new List<WConstraintDefinition>
{
new WUniqueConstraintDefinition
{
Clustered = true,
IsPrimaryKey = true
}
}
},
new WColumnDefinition
{
ColumnIdentifier = new Identifier {Value = "srcCnt"},
DataType = new WParameterizedDataTypeReference
{
Name = new WSchemaObjectName(new Identifier {Value = "int"}),
},
},
},
Indexes = new List<WIndexDefinition>(),
TableConstraints = new List<WConstraintDefinition>()
}
});
var tableVar = new WSpecialNamedTableReference
{
TableObjectName = new WSchemaObjectName(new Identifier { Value = "@" + deleteEdgeTempTable + "_1" })
};
var reversedTableVar = new WSpecialNamedTableReference
{
TableObjectName = new WSchemaObjectName(new Identifier { Value = "@" + deleteEdgeTempTable + "_2" })
};
WInsertSpecification[] insertStat = new WInsertSpecification[]
{
new WInsertSpecification
{
Target = tableVar,
InsertSource = new WSelectInsertSource
{
Select = edgeSelectQuery
}
},
new WInsertSpecification
{
Target = reversedTableVar,
InsertSource = new WSelectInsertSource
{
Select = reversedEdgeSelectQuery
}
}
};
// Update statments for edge and reversed edge
WUpdateSpecification[] updateStat = new WUpdateSpecification[]
{
new WUpdateSpecification
{
Target = new WNamedTableReference
{
TableObjectName = sourceNameTable.TableObjectName
},
SetClauses = new List<WSetClause> {setClauses[0], setClauses[2]},
FromClause = new WFromClause
{
TableReferences = new WTableReference[]
{
new WQueryDerivedTable
{
QueryExpr = new WSelectQueryBlock
{
SelectElements = new List<WSelectElement>()
{
new WSelectStarExpression()
},
FromClause = new WFromClause
{
TableReferences = new List<WTableReference> {tableVar}
}
},
Alias = new Identifier {Value = deleteEdgeTableName},
},
}
},
WhereClause = whereClause,
TopRowFilter = node.TopRowFilter
},
new WUpdateSpecification
{
Target = new WNamedTableReference
{
TableObjectName = sinkNameTable.TableObjectName
},
SetClauses = new List<WSetClause> {setClauses[1]},
FromClause = new WFromClause
{
TableReferences = new WTableReference[]
{
new WQueryDerivedTable
{
Alias = new Identifier {Value = deleteEdgeTableName},
QueryExpr = new WSelectQueryBlock
{
SelectElements = new List<WSelectElement>()
{
new WSelectStarExpression()
},
FromClause = new WFromClause
{
TableReferences = new List<WTableReference> {reversedTableVar}
}
}
},
}
},
WhereClause = whereClause,
TopRowFilter = node.TopRowFilter
},
};
bool sourceFirst = compare < 0;
if (sourceFirst)
{
// With expression
res.Add(deleteCommonTableExpr);
res.Add(insertStat[0]);
res.Add(updateStat[0]);
res.Add(new WSqlUnknownStatement
{
Statement = String.Format("DELETE FROM @{0}_1", deleteEdgeTempTable)
});
// With expression
res.Add(deleteCommonTableExpr);
res.Add(insertStat[1]);
res.Add(updateStat[1]);
res.Add(new WSqlUnknownStatement
{
Statement = String.Format("DELETE FROM @{0}_2", deleteEdgeTempTable)
});
}
else
{
// With expression
res.Add(deleteCommonTableExpr);
res.Add(insertStat[1]);
res.Add(updateStat[1]);
res.Add(new WSqlUnknownStatement
{
Statement = String.Format("DELETE FROM @{0}_2", deleteEdgeTempTable)
});
// With expression
res.Add(deleteCommonTableExpr);
res.Add(insertStat[0]);
res.Add(updateStat[0]);
res.Add(new WSqlUnknownStatement
{
Statement = String.Format("DELETE FROM @{0}_1", deleteEdgeTempTable)
});
}
}
}
private void UpdateMapping(WSelectQueryBlock expr)
{
if (expr == null)
{
throw new EdgeViewException("Invalid Select Statement in CREATE NODE VIEW");
}
if (expr.FromClause.TableReferences.Count != 1)
{
throw new EdgeViewException(
"Only one node table can be specified in each select statemtn of CREATE NODE VIEW");
}
var tableRef = expr.FromClause.TableReferences.First() as WNamedTableReference;
if (tableRef == null)
{
throw new EdgeViewException("Invalid node table");
}
var schema = tableRef.TableObjectName.DatabaseIdentifier == null
? "dbo"
: tableRef.TableObjectName.DatabaseIdentifier.Value;
if (string.Compare(schema, _schema, StringComparison.OrdinalIgnoreCase) != 0)
{
throw new NodeViewException("All the node tables should be in the same schema as the node view");
}
var tableRefName = tableRef.TableObjectName.SchemaIdentifier.Value;
var edgeName = tableRef.TableObjectName.BaseIdentifier.Value;
_edges.Add(new Tuple <string, string>(tableRefName, edgeName));
if (_defaultMerge)
{
if (expr.SelectElements.Count != 1)
{
throw new EdgeViewException(
"Select element in each statement should be consistent to the first statement");
}
if (!(expr.SelectElements.First() is WSelectStarExpression))
{
throw new EdgeViewException(
"Select element should be '*' for " + tableRefName + "." + edgeName);
}
}
else if (_noAttributes)
{
if (expr.SelectElements.Count != 1)
{
throw new EdgeViewException(
"Select element in each statement should be consistent to the first statement");
}
var element = expr.SelectElements.First();
var valueExpr = element as WSelectScalarExpression;
if (valueExpr == null)
{
throw new EdgeViewException(
"Select element should be null for " + tableRefName + "." + edgeName);
}
var nullExpr = valueExpr.SelectExpr as WValueExpression;
if (nullExpr == null || nullExpr.Value.ToLower() != "null")
{
throw new EdgeViewException(
"Select element should be null for " + tableRefName + "." + edgeName);
}
}
else if (!_attributeMapping.Any())
{
if (expr.SelectElements.Count == 1 && expr.SelectElements.First() is WSelectStarExpression)
{
_defaultMerge = true;
return;
}
foreach (var selectElement in expr.SelectElements)
{
var scalarElement = selectElement as WSelectScalarExpression;
if (scalarElement == null)
{
throw new EdgeViewException("Invalid select element");
}
string newColName = scalarElement.ColumnName;
var oldColRefExpression = scalarElement.SelectExpr as WColumnReferenceExpression;
if (oldColRefExpression == null)
{
var oldColValueExpression = scalarElement.SelectExpr as WValueExpression;
if (oldColValueExpression == null)
{
throw new NodeViewException(
"Each select element should be null or reference to a column");
}
if (oldColValueExpression.Value.ToLower() != "null")
{
throw new NodeViewException(
"Each select element should be null or reference to a column");
}
if (string.IsNullOrEmpty(newColName))
{
if (expr.SelectElements.Count == 1)
{
_noAttributes = true;
return;
}
throw new EdgeViewException(
"Column name should be specified for the first select null expression");
}
_attributeMapping.Add(
new Tuple <string, List <Tuple <string, string, string> > >(newColName.ToLower(),
new List <Tuple <string, string, string> >()));
}
else
{
string oldColName = oldColRefExpression.MultiPartIdentifier.Identifiers.Last().Value;
if (string.IsNullOrEmpty(newColName))
{
newColName = oldColName;
}
_attributeMapping.Add(
new Tuple <string, List <Tuple <string, string, string> > >(newColName.ToLower(),
new List <Tuple <string, string, string> >
{
new Tuple <string, string, string>(tableRefName.ToLower(), edgeName.ToLower(),
oldColName.ToLower())
}));
}
_edgeAttribute.Add(newColName);
}
}
else
{
for (int i = 0; i < expr.SelectElements.Count; i++)
{
var scalarElement = expr.SelectElements[i] as WSelectScalarExpression;
if (scalarElement == null)
{
throw new NodeViewException("Invalid select element");
}
var oldColRefExpression = scalarElement.SelectExpr as WColumnReferenceExpression;
if (oldColRefExpression == null)
{
var oldColValueExpression = scalarElement.SelectExpr as WValueExpression;
if (oldColValueExpression == null || oldColValueExpression.Value.ToLower() != "null")
{
throw new EdgeViewException(
"Each select element should be null or reference to a column");
}
}
else
{
string oldColName = oldColRefExpression.MultiPartIdentifier.Identifiers.Last().Value;
_attributeMapping[i].Item2.Add(new Tuple <string, string, string>(tableRefName.ToLower(),
edgeName.ToLower(),
oldColName.ToLower()));
}
}
}
//expr.SelectElements.Add(new WSelectScalarExpression
//{
// SelectExpr =
// new WColumnReferenceExpression
// {
// MultiPartIdentifier = new WMultiPartIdentifier(new Identifier {Value = "Sink"})
// }
//});
//expr.SelectElements.Add(new WSelectScalarExpression
//{
// SelectExpr =
// new WColumnReferenceExpression
// {
// MultiPartIdentifier = new WMultiPartIdentifier(new Identifier { Value = "Src" })
// }
//});
//expr.FromClause.TableReferences[0] = new WNamedTableReference
//{
// TableObjectName =
// new WSchemaObjectName(new Identifier
// {
// Value = string.Format("{0}_{1}_{2}_Sampling", schema, tableRefName, edgeName)
// })
//};
}
public virtual void Visit(WSelectQueryBlock node)
{
node.AcceptChildren(this);
}
private WCommonTableExpression ConstructDeleteEdgeSelect(WSelectQueryBlock node, string edgeAlias, string tempTableName
,out WTableReference sinkTable, out WTableReference sourceTable)
{
sourceTable = null;
sinkTable = null;
var sourceTableScalar = node.SelectElements[0] as WSelectScalarExpression;
if (sourceTableScalar == null)
return null;
var sourceTableColumn = sourceTableScalar.SelectExpr as WColumnReferenceExpression;
if (sourceTableColumn == null)
return null;
var sourceTableName = sourceTableColumn.MultiPartIdentifier.Identifiers.Last().Value;
var sourceNodeIdExpr = new WColumnReferenceExpression();
foreach (var identifier in sourceTableColumn.MultiPartIdentifier.Identifiers)
sourceNodeIdExpr.Add(identifier);
sourceNodeIdExpr.AddIdentifier("GlobalNodeId");
var collectVarVisitor = new CollectVariableVisitor();
var context = collectVarVisitor.Invoke(node);
if (!context.NodeTableDictionary.Any())
{
throw new GraphViewException("Missing From Clause in Delete Edge statement");
}
WColumnReferenceExpression sinkNodeIdExpr = null;
sourceTable = context[sourceTableName];
var groupByParams = new List<WScalarExpression>();
for (var index = 1; index < node.SelectElements.Count; ++index)
{
var element = node.SelectElements[index] as WSelectScalarExpression;
if (element == null)
return null;
//sink table
if (index == 1)
{
var sinkTableColumn = element.SelectExpr as WColumnReferenceExpression;
if (sinkTableColumn == null)
return null;
var sinkTableName = sinkTableColumn.MultiPartIdentifier.Identifiers.Last().Value;
sinkTable = context[sinkTableName];
sinkNodeIdExpr = new WColumnReferenceExpression();
foreach (var identifier in sinkTableColumn.MultiPartIdentifier.Identifiers)
sinkNodeIdExpr.Add(identifier);
sinkNodeIdExpr.AddIdentifier("GlobalNodeId");
}
}
var sourceNodeId = new WSelectScalarExpression
{
SelectExpr = sourceNodeIdExpr,
ColumnName = "src",
};
var sinkNodeId = new WSelectScalarExpression
{
SelectExpr = sinkNodeIdExpr,
ColumnName = "sink"
};
var edgeId = new WSelectScalarExpression
{
SelectExpr = new WColumnReferenceExpression
{
MultiPartIdentifier = new WMultiPartIdentifier(
new Identifier[]
{
new Identifier {Value = edgeAlias},
new Identifier {Value = "Edgeid"}
}
)
},
ColumnName = "edgeid"
};
var elements = new List<WSelectElement>
{
sourceNodeId,
sinkNodeId,
edgeId
};
return new WCommonTableExpression
{
ExpressionName = new Identifier { Value = tempTableName },
QueryExpression = new WSelectQueryBlock
{
FromClause = node.FromClause,
WhereClause = new WWhereClause
{
SearchCondition = node.WhereClause.SearchCondition
},
HavingClause = node.HavingClause,
OrderByClause = node.OrderByClause,
TopRowFilter = node.TopRowFilter,
UniqueRowFilter = node.UniqueRowFilter,
SelectElements = elements,
MatchClause = node.MatchClause,
}
};
}
// Repeat algorithm
// Firstly, we generate the repeatQueryBlock in order that we can get the initial query
// Secondly, we generate the inputVariableVistorMap via repeatInputVariable.ProjectedProperties,
// untilInputVariable.ProjectedProperties, emitInputVariable.ProjectedProperties and ProjectedProperties.
// Generally, these properties are related to the input every time, but in repeatQueryBlock, these are
// just related to the input of the first time. Therefore, we need to replace these after.
// Thirdly, we need to generate the firstQueryExpr and the selectColumnExpr of repeatQueryBlock. Pay
// attention, we need to repeatQueryBlock again because we need more properties about the output of
// the last step in repeat-step. These properties are populated in the second step.
// Fourthly, we use the inputVariableVistorMap to replace the columns in the repeatQueryBlock. But we
// should not change the columns in path-step. Because if we generate the path in the repeat-step, the
// path consists of
// 1. the previous steps before the repeat-step
// 2. the local path(_path) in the repeat-step
// Keep in mind that the initial _path is null, the _path includes all steps as long as they are in
// the repeat-step except for the first input. And the _path after the first pass includes the last step
// in the repeat-step. So the path must include the two part. That means all columns in path-step should
// not be replaced. Here, we use the ModifyRepeatInputVariablesVisitor to finish this work. If it visits
// WPathTableReference, it does nothing, otherwise, it will replace the columns according to the
// inputVariableVistorMap.
public override WTableReference ToTableReference()
{
//The following two variables are used for manually creating SelectScalarExpression of repeat
List <WSelectScalarExpression> firstSelectList = new List <WSelectScalarExpression>();
List <WSelectScalarExpression> secondSelectList = new List <WSelectScalarExpression>();
WScalarExpression firstSelectColumn, secondSelectColumn, firstExpr, secondExpr;
// The following map is used to replace columns of the first input to columns of the repeat input
// such as N_0.id -> R.key_0
string aliasName;
Tuple <string, string> key, value;
Dictionary <Tuple <string, string>, Tuple <string, string> > inputVariableVistorMap =
new Dictionary <Tuple <string, string>, Tuple <string, string> >();
// We should generate the syntax tree firstly
// Some variables will populate ProjectProperty only when we call the ToTableReference function where they appear.
WRepeatConditionExpression repeatConditionExpr = this.GetRepeatConditionExpression();
WSelectQueryBlock repeatQueryBlock = this.RepeatContext.ToSelectQueryBlock();
GremlinVariable repeatInputVariable = this.RepeatContext.VariableList.First();
GremlinVariable repeatOutputVariable = this.RepeatContext.PivotVariable;
GremlinVariable realInputVariable = this.InputVariable.RealVariable;
GremlinVariable repeatPivotVariable = this.RepeatContext.PivotVariable;
// this.DefaultProperty
key = new Tuple <string, string>(this.GetVariableName(), this.DefaultProperty());
value = key;
inputVariableVistorMap[key] = value;
key = new Tuple <string, string>(realInputVariable.GetVariableName(), realInputVariable.DefaultProperty());
value = new Tuple <string, string>(GremlinKeyword.RepeatInitalTableName, this.DefaultProperty());
inputVariableVistorMap[key] = value;
firstExpr = realInputVariable.DefaultProjection().ToScalarExpression();
secondExpr = repeatOutputVariable.DefaultProjection().ToScalarExpression();
firstSelectList.Add(SqlUtil.GetSelectScalarExpr(firstExpr, this.DefaultProperty()));
secondSelectList.Add(SqlUtil.GetSelectScalarExpr(secondExpr, this.DefaultProperty()));
foreach (string property in this.ProjectedProperties)
{
if (property == GremlinKeyword.Path)
{
firstSelectList.Add(SqlUtil.GetSelectScalarExpr(SqlUtil.GetValueExpr(null), GremlinKeyword.Path));
secondSelectList.Add(
SqlUtil.GetSelectScalarExpr(
this.RepeatContext.ContextLocalPath.DefaultProjection().ToScalarExpression(),
GremlinKeyword.Path));
}
else
{
key = new Tuple <string, string>(this.GetVariableName(), property);
value = key;
inputVariableVistorMap[key] = value;
key = new Tuple <string, string>(realInputVariable.GetVariableName(), property);
value = new Tuple <string, string>(GremlinKeyword.RepeatInitalTableName, property);
inputVariableVistorMap[key] = value;
firstExpr = realInputVariable.ProjectedProperties.Contains(property)
? realInputVariable.GetVariableProperty(property).ToScalarExpression()
: SqlUtil.GetValueExpr(null);
secondExpr = repeatOutputVariable.ProjectedProperties.Contains(property)
? this.RepeatContext.PivotVariable.GetVariableProperty(property).ToScalarExpression()
: SqlUtil.GetValueExpr(null);
firstSelectList.Add(SqlUtil.GetSelectScalarExpr(firstExpr, property));
secondSelectList.Add(SqlUtil.GetSelectScalarExpr(secondExpr, property));
}
}
// repeatInputVariable.DefaultProperty()
key = new Tuple <string, string>(repeatInputVariable.GetVariableName(), repeatInputVariable.DefaultProperty());
if (!inputVariableVistorMap.Keys.Contains(key))
{
aliasName = this.GenerateKey();
value = new Tuple <string, string>(GremlinKeyword.RepeatInitalTableName, aliasName);
inputVariableVistorMap[key] = value;
firstSelectColumn = repeatInputVariable.DefaultProjection().ToScalarExpression() as WColumnReferenceExpression;
secondSelectColumn = repeatPivotVariable.DefaultProjection().ToScalarExpression() as WColumnReferenceExpression;
firstSelectList.Add(SqlUtil.GetSelectScalarExpr(firstSelectColumn, aliasName));
secondSelectList.Add(SqlUtil.GetSelectScalarExpr(secondSelectColumn, aliasName));
}
foreach (string property in repeatInputVariable.ProjectedProperties)
{
key = new Tuple <string, string>(repeatInputVariable.GetVariableName(), property);
if (!inputVariableVistorMap.Keys.Contains(key))
{
aliasName = this.GenerateKey();
value = new Tuple <string, string>(GremlinKeyword.RepeatInitalTableName, aliasName);
inputVariableVistorMap[key] = value;
firstSelectColumn = repeatInputVariable.GetVariableProperty(property).ToScalarExpression() as WColumnReferenceExpression;
secondSelectColumn = repeatPivotVariable.GetVariableProperty(property).ToScalarExpression() as WColumnReferenceExpression;
firstSelectList.Add(SqlUtil.GetSelectScalarExpr(firstSelectColumn, aliasName));
secondSelectList.Add(SqlUtil.GetSelectScalarExpr(secondSelectColumn, aliasName));
}
}
if (this.RepeatCondition.TerminationContext != null && this.RepeatCondition.TerminationContext.VariableList.Count > 0)
{
GremlinVariable untilInputVariable = this.RepeatCondition.TerminationContext.VariableList.First();
// untilInputVariable.DefaultProperty()
key = new Tuple <string, string>(untilInputVariable.GetVariableName(), untilInputVariable.DefaultProperty());
if (!inputVariableVistorMap.Keys.Contains(key))
{
aliasName = this.GenerateKey();
value = new Tuple <string, string>(GremlinKeyword.RepeatInitalTableName, aliasName);
inputVariableVistorMap[key] = value;
firstSelectColumn =
untilInputVariable.DefaultProjection().ToScalarExpression() as WColumnReferenceExpression;
secondSelectColumn =
repeatPivotVariable.DefaultProjection().ToScalarExpression() as WColumnReferenceExpression;
firstSelectList.Add(SqlUtil.GetSelectScalarExpr(firstSelectColumn, aliasName));
secondSelectList.Add(SqlUtil.GetSelectScalarExpr(secondSelectColumn, aliasName));
}
foreach (string property in untilInputVariable.ProjectedProperties)
{
key = new Tuple <string, string>(untilInputVariable.GetVariableName(), property);
if (!inputVariableVistorMap.Keys.Contains(key))
{
aliasName = this.GenerateKey();
value = new Tuple <string, string>(GremlinKeyword.RepeatInitalTableName, aliasName);
inputVariableVistorMap[key] = value;
firstSelectColumn = untilInputVariable.GetVariableProperty(property).ToScalarExpression() as WColumnReferenceExpression;
secondSelectColumn = repeatPivotVariable.GetVariableProperty(property).ToScalarExpression() as WColumnReferenceExpression;
firstSelectList.Add(SqlUtil.GetSelectScalarExpr(firstSelectColumn, aliasName));
secondSelectList.Add(SqlUtil.GetSelectScalarExpr(secondSelectColumn, aliasName));
}
}
}
if (this.RepeatCondition.EmitContext != null && this.RepeatCondition.EmitContext.VariableList.Count > 0)
{
GremlinVariable emitInputVariable = this.RepeatCondition.EmitContext.VariableList.First();
// emitInputVariable.DefaultProperty()
key = new Tuple <string, string>(emitInputVariable.GetVariableName(), emitInputVariable.DefaultProperty());
if (!inputVariableVistorMap.Keys.Contains(key))
{
aliasName = this.GenerateKey();
value = new Tuple <string, string>(GremlinKeyword.RepeatInitalTableName, aliasName);
inputVariableVistorMap[key] = value;
firstSelectColumn =
emitInputVariable.DefaultProjection().ToScalarExpression() as WColumnReferenceExpression;
secondSelectColumn =
repeatPivotVariable.DefaultProjection().ToScalarExpression() as WColumnReferenceExpression;
firstSelectList.Add(SqlUtil.GetSelectScalarExpr(firstSelectColumn, aliasName));
secondSelectList.Add(SqlUtil.GetSelectScalarExpr(secondSelectColumn, aliasName));
}
foreach (string property in emitInputVariable.ProjectedProperties)
{
key = new Tuple <string, string>(emitInputVariable.GetVariableName(), property);
if (!inputVariableVistorMap.Keys.Contains(key))
{
aliasName = this.GenerateKey();
value = new Tuple <string, string>(GremlinKeyword.RepeatInitalTableName, aliasName);
inputVariableVistorMap[key] = value;
firstSelectColumn =
emitInputVariable.GetVariableProperty(property).ToScalarExpression() as WColumnReferenceExpression;
secondSelectColumn =
repeatPivotVariable.GetVariableProperty(property).ToScalarExpression() as WColumnReferenceExpression;
firstSelectList.Add(SqlUtil.GetSelectScalarExpr(firstSelectColumn, aliasName));
secondSelectList.Add(SqlUtil.GetSelectScalarExpr(secondSelectColumn, aliasName));
}
}
}
WSelectQueryBlock firstQueryExpr = new WSelectQueryBlock();
foreach (WSelectScalarExpression selectColumnExpr in firstSelectList)
{
firstQueryExpr.SelectElements.Add(selectColumnExpr);
}
repeatQueryBlock = this.RepeatContext.ToSelectQueryBlock();
repeatQueryBlock.SelectElements.Clear();
foreach (WSelectScalarExpression selectColumnExpr in secondSelectList)
{
repeatQueryBlock.SelectElements.Add(selectColumnExpr);
}
//Then we will use the inputVariableVistorMap to replace ColumnRefernceExpression in the syntax tree
//which matchs n_0.id to R_0.key_0 except for WPathTableReference
new ModifyRepeatInputVariablesVisitor().Invoke(repeatQueryBlock, inputVariableVistorMap);
new ModifyRepeatInputVariablesVisitor().Invoke(repeatConditionExpr, inputVariableVistorMap);
List <WScalarExpression> repeatParameters = new List <WScalarExpression>()
{
SqlUtil.GetScalarSubquery(SqlUtil.GetBinaryQueryExpr(firstQueryExpr, repeatQueryBlock)),
repeatConditionExpr
};
WSchemaObjectFunctionTableReference tableRef = SqlUtil.GetFunctionTableReference(GremlinKeyword.func.Repeat, repeatParameters, this.GetVariableName());
return(SqlUtil.GetCrossApplyTableReference(tableRef));
}
private void UpdateMapping(WSelectQueryBlock expr)
{
if (expr == null)
throw new EdgeViewException("Invalid Select Statement in CREATE NODE VIEW");
if (expr.FromClause.TableReferences.Count != 1)
throw new EdgeViewException(
"Only one node table can be specified in each select statemtn of CREATE NODE VIEW");
var tableRef = expr.FromClause.TableReferences.First() as WNamedTableReference;
if (tableRef == null)
throw new EdgeViewException("Invalid node table");
var schema = tableRef.TableObjectName.DatabaseIdentifier == null
? "dbo"
: tableRef.TableObjectName.DatabaseIdentifier.Value;
if (string.Compare(schema, _schema, StringComparison.OrdinalIgnoreCase) != 0)
throw new NodeViewException("All the node tables should be in the same schema as the node view");
var tableRefName = tableRef.TableObjectName.SchemaIdentifier.Value;
var edgeName = tableRef.TableObjectName.BaseIdentifier.Value;
_edges.Add(new Tuple<string, string>(tableRefName, edgeName));
if (_defaultMerge)
{
if (expr.SelectElements.Count != 1)
throw new EdgeViewException(
"Select element in each statement should be consistent to the first statement");
if (!(expr.SelectElements.First() is WSelectStarExpression))
throw new EdgeViewException(
"Select element should be '*' for " + tableRefName + "." + edgeName);
}
else if (_noAttributes)
{
if (expr.SelectElements.Count != 1)
throw new EdgeViewException(
"Select element in each statement should be consistent to the first statement");
var element = expr.SelectElements.First();
var valueExpr = element as WSelectScalarExpression;
if (valueExpr == null)
throw new EdgeViewException(
"Select element should be null for " + tableRefName + "." + edgeName);
var nullExpr = valueExpr.SelectExpr as WValueExpression;
if (nullExpr == null || nullExpr.Value.ToLower()!="null")
throw new EdgeViewException(
"Select element should be null for " + tableRefName + "." + edgeName);
}
else if (!_attributeMapping.Any())
{
if (expr.SelectElements.Count == 1 && expr.SelectElements.First() is WSelectStarExpression)
{
_defaultMerge = true;
return;
}
foreach (var selectElement in expr.SelectElements)
{
var scalarElement = selectElement as WSelectScalarExpression;
if (scalarElement == null)
throw new EdgeViewException("Invalid select element");
string newColName = scalarElement.ColumnName;
var oldColRefExpression = scalarElement.SelectExpr as WColumnReferenceExpression;
if (oldColRefExpression == null)
{
var oldColValueExpression = scalarElement.SelectExpr as WValueExpression;
if (oldColValueExpression == null)
throw new NodeViewException(
"Each select element should be null or reference to a column");
if (oldColValueExpression.Value.ToLower() != "null")
throw new NodeViewException(
"Each select element should be null or reference to a column");
if (string.IsNullOrEmpty(newColName))
{
if (expr.SelectElements.Count == 1)
{
_noAttributes = true;
return;
}
throw new EdgeViewException(
"Column name should be specified for the first select null expression");
}
_attributeMapping.Add(
new Tuple<string, List<Tuple<string, string, string>>>(newColName.ToLower(),
new List<Tuple<string, string, string>>()));
}
else
{
string oldColName = oldColRefExpression.MultiPartIdentifier.Identifiers.Last().Value;
if (string.IsNullOrEmpty(newColName))
newColName = oldColName;
_attributeMapping.Add(
new Tuple<string, List<Tuple<string, string, string>>>(newColName.ToLower(),
new List<Tuple<string, string, string>>
{
new Tuple<string, string, string>(tableRefName.ToLower(), edgeName.ToLower(),
oldColName.ToLower())
}));
}
_edgeAttribute.Add(newColName);
}
}
else
{
for (int i = 0; i < expr.SelectElements.Count; i++)
{
var scalarElement = expr.SelectElements[i] as WSelectScalarExpression;
if (scalarElement == null)
throw new NodeViewException("Invalid select element");
var oldColRefExpression = scalarElement.SelectExpr as WColumnReferenceExpression;
if (oldColRefExpression == null)
{
var oldColValueExpression = scalarElement.SelectExpr as WValueExpression;
if (oldColValueExpression == null || oldColValueExpression.Value.ToLower() != "null")
throw new EdgeViewException(
"Each select element should be null or reference to a column");
}
else
{
string oldColName = oldColRefExpression.MultiPartIdentifier.Identifiers.Last().Value;
_attributeMapping[i].Item2.Add(new Tuple<string, string, string>(tableRefName.ToLower(),
edgeName.ToLower(),
oldColName.ToLower()));
}
}
}
//expr.SelectElements.Add(new WSelectScalarExpression
//{
// SelectExpr =
// new WColumnReferenceExpression
// {
// MultiPartIdentifier = new WMultiPartIdentifier(new Identifier {Value = "Sink"})
// }
//});
//expr.SelectElements.Add(new WSelectScalarExpression
//{
// SelectExpr =
// new WColumnReferenceExpression
// {
// MultiPartIdentifier = new WMultiPartIdentifier(new Identifier { Value = "Src" })
// }
//});
//expr.FromClause.TableReferences[0] = new WNamedTableReference
//{
// TableObjectName =
// new WSchemaObjectName(new Identifier
// {
// Value = string.Format("{0}_{1}_{2}_Sampling", schema, tableRefName, edgeName)
// })
//};
}
private WMultiCommonTableExpression ConstructDeleteEdgeSelect(WSelectQueryBlock node, WEdgeColumnReferenceExpression edgeCol, string tempTableName
,out WTableReference sinkTable, out WTableReference sourceTable, ref bool hasReversedEdge)
{
sourceTable = null;
sinkTable = null;
string sourceTableName = null;
string sinkTableName = null;
var sourceTableScalar = node.SelectElements[0] as WSelectScalarExpression;
if (sourceTableScalar == null)
return null;
var sourceTableColumn = sourceTableScalar.SelectExpr as WColumnReferenceExpression;
if (sourceTableColumn == null)
return null;
sourceTableName = sourceTableColumn.MultiPartIdentifier.Identifiers.Last().Value;
var sourceNodeIdExpr = new WColumnReferenceExpression();
foreach (var identifier in sourceTableColumn.MultiPartIdentifier.Identifiers)
sourceNodeIdExpr.Add(identifier);
sourceNodeIdExpr.AddIdentifier("GlobalNodeId");
var collectVarVisitor = new CollectVariableVisitor();
var context = collectVarVisitor.Invoke(node);
if (!context.NodeTableDictionary.Any())
{
throw new GraphViewException("Missing From Clause in Delete Edge statement");
}
WColumnReferenceExpression sinkNodeIdExpr = null;
sourceTable = context[sourceTableName];
var groupByParams = new List<WScalarExpression>();
for (var index = 1; index < node.SelectElements.Count; ++index)
{
var element = node.SelectElements[index] as WSelectScalarExpression;
if (element == null)
return null;
//sink table
if (index == 1)
{
var sinkTableColumn = element.SelectExpr as WColumnReferenceExpression;
if (sinkTableColumn == null)
return null;
sinkTableName = sinkTableColumn.MultiPartIdentifier.Identifiers.Last().Value;
sinkTable = context[sinkTableName];
sinkNodeIdExpr = new WColumnReferenceExpression();
foreach (var identifier in sinkTableColumn.MultiPartIdentifier.Identifiers)
sinkNodeIdExpr.Add(identifier);
sinkNodeIdExpr.AddIdentifier("GlobalNodeId");
}
}
var sourceNodeId = new WSelectScalarExpression
{
SelectExpr = sourceNodeIdExpr,
ColumnName = "src",
};
var sinkNodeId = new WSelectScalarExpression
{
SelectExpr = sinkNodeIdExpr,
ColumnName = "sink"
};
var edgeId = new WSelectScalarExpression
{
SelectExpr = new WColumnReferenceExpression
{
MultiPartIdentifier = new WMultiPartIdentifier(
new Identifier[]
{
new Identifier {Value = edgeCol.Alias??string.Format("{0}_{1}_{2}",sourceTableName,edgeCol.MultiPartIdentifier.Identifiers.Last().Value,sinkTableName)},
new Identifier {Value = "Edgeid"}
})
},
ColumnName = "edgeid"
};
var sourceTableNameRef = sourceTable as WNamedTableReference;
if (sourceTableNameRef == null)
throw new GraphViewException("Source table of DELETE EDGE statement should be a named table reference.");
var sinkTableNameRef = sinkTable as WNamedTableReference;
if (sinkTableNameRef == null)
throw new GraphViewException("Sink table of DELETE EDGE statement should be a named table reference.");
int compare = string.CompareOrdinal(sourceTableNameRef.TableObjectName.ToString(), sinkTableNameRef.TableObjectName.ToString());
using (var command = Tx.Connection.CreateCommand())
{
command.Transaction = Tx;
command.Parameters.AddWithValue("@schema", WNamedTableReference.SchemaNameToTuple(sourceTableNameRef.TableObjectName).Item1);
command.Parameters.AddWithValue("@tableName", sourceTableNameRef.TableObjectName.Identifiers.Last().Value);
command.Parameters.AddWithValue("@colName", edgeCol.MultiPartIdentifier.Identifiers.Last().Value);
command.Parameters.AddWithValue("@role", WNodeTableColumnRole.Edge);
command.CommandText = string.Format(@"
SELECT NodeColumn.HasReversedEdge
FROM [{0}] AS NodeColumn
WHERE NodeColumn.TableSchema = @schema and
NodeColumn.TableName = @tableName and
NodeColumn.ColumnName = @colName and
NodeColumn.ColumnRole = @role",
GraphViewConnection.MetadataTables[1]);
using (var reader = command.ExecuteReader())
{
if (reader.Read())
{
hasReversedEdge = bool.Parse(reader[0].ToString());
}
}
}
var reversedEdgeName = sourceTableNameRef.TableObjectName.Identifiers.Last().Value +
"_" + edgeCol.MultiPartIdentifier.Identifiers.Last().Value + "Reversed";
var reversedEdgeId = new WSelectScalarExpression
{
SelectExpr = new WColumnReferenceExpression
{
MultiPartIdentifier = new WMultiPartIdentifier(
new Identifier[]
{
new Identifier {Value = edgeCol.Alias??string.Format("{0}_{1}_{2}",sourceTableName,edgeCol.MultiPartIdentifier.Identifiers.Last().Value,sinkTableName)},
new Identifier {Value = "Edgeid"}
})
},
ColumnName = "edgeid"
};
var elements = new List<WSelectElement>
{
sourceNodeId,
sinkNodeId,
edgeId
};
var reversedElements = new List<WSelectElement>
{
sourceNodeId,
sinkNodeId,
reversedEdgeId,
};
return new WMultiCommonTableExpression
{
WCommonTableExpressions = new List<WCommonTableExpression>()
{
new WCommonTableExpression
{
ExpressionName = new Identifier
{
Value = hasReversedEdge && compare == 0 ? tempTableName + "_1" : tempTableName
},
QueryExpression = new WSelectQueryBlock
{
FromClause = node.FromClause,
WhereClause = new WWhereClause
{
SearchCondition = node.WhereClause.SearchCondition
},
HavingClause = node.HavingClause,
OrderByClause = node.OrderByClause,
TopRowFilter = node.TopRowFilter,
UniqueRowFilter = node.UniqueRowFilter,
SelectElements = elements,
MatchClause = node.MatchClause,
}
},
new WCommonTableExpression
{
ExpressionName = new Identifier
{
Value = hasReversedEdge && compare == 0 ? tempTableName + "_2" : tempTableName
},
QueryExpression = new WSelectQueryBlock
{
FromClause = node.FromClause,
WhereClause = hasReversedEdge ?
new WWhereClause { SearchCondition = ObjectExtensions.Copy(node.WhereClause.SearchCondition), }
: node.WhereClause,
HavingClause = node.HavingClause,
OrderByClause = node.OrderByClause,
TopRowFilter = node.TopRowFilter,
UniqueRowFilter = node.UniqueRowFilter,
SelectElements = hasReversedEdge ? reversedElements : elements,
MatchClause = hasReversedEdge? ConstructReversedMatchClause(node, context) : node.MatchClause,
}
},
}
};
}
public override WTableReference ToTableReference()
{
if (RepeatContext.ContextLocalPath != null)
{
RepeatContext.ContextLocalPath.PathList.Insert(0, null);
RepeatContext.ContextLocalPath.IsInRepeatContext = true;
}
//The following two variables are used for manually creating SelectScalarExpression of repeat
List <WSelectScalarExpression> repeatFirstSelect = new List <WSelectScalarExpression>();
List <WSelectScalarExpression> repeatSecondSelect = new List <WSelectScalarExpression>();
// The following two variables are used for Generating a Map
// such as N_0.id -> key_0
// Then we will use this map to replace ColumnRefernceExpression in the syntax tree which matchs n_0.id to R_0.key_0
Dictionary <WColumnReferenceExpression, string> repeatVistorMap = new Dictionary <WColumnReferenceExpression, string>();
Dictionary <WColumnReferenceExpression, string> conditionVistorMap = new Dictionary <WColumnReferenceExpression, string>();
//We should generate the syntax tree firstly
//Some variables will populate ProjectProperty only when we call the ToTableReference function where they appear.
WRepeatConditionExpression repeatConditionExpr = GetRepeatConditionExpression();
WSelectQueryBlock repeatQueryBlock = RepeatContext.ToSelectQueryBlock();
// TODO: explain this step in detail
var repeatNewToOldSelectedVarMap = GetNewToOldSelectedVarMap(RepeatContext);
if (!repeatNewToOldSelectedVarMap.ContainsKey(RepeatContext.PivotVariable))
{
repeatNewToOldSelectedVarMap[RepeatContext.PivotVariable] = RepeatContext.VariableList.First();
}
foreach (var pair in repeatNewToOldSelectedVarMap)
{
GremlinVariable newVariable = pair.Key;
GremlinVariable oldVariable = pair.Value;
foreach (var property in pair.Value.ProjectedProperties)
{
var aliasName = GenerateKey();
var firstSelectColumn = oldVariable.GetVariableProperty(property).ToScalarExpression() as WColumnReferenceExpression;
var secondSelectColumn = newVariable.GetVariableProperty(property).ToScalarExpression() as WColumnReferenceExpression;
repeatFirstSelect.Add(SqlUtil.GetSelectScalarExpr(firstSelectColumn, aliasName));
repeatSecondSelect.Add(SqlUtil.GetSelectScalarExpr(secondSelectColumn, aliasName));
repeatVistorMap[firstSelectColumn.Copy()] = aliasName;
}
}
if (RepeatCondition.TerminationContext != null && RepeatCondition.TerminationContext.VariableList.Count > 0)
{
var terminatedNewToOldSelectedVarMap = GetNewToOldSelectedVarMap(RepeatCondition.TerminationContext);
if (!terminatedNewToOldSelectedVarMap.ContainsKey(RepeatContext.PivotVariable))
{
terminatedNewToOldSelectedVarMap[RepeatContext.PivotVariable] = RepeatCondition.TerminationContext.VariableList.First();
}
foreach (var pair in terminatedNewToOldSelectedVarMap)
{
GremlinVariable newVariable = pair.Key;
GremlinVariable oldVariable = pair.Value;
foreach (var property in oldVariable.ProjectedProperties)
{
var aliasName = GenerateKey();
var firstSelectColumn = RepeatCondition.StartFromContext
? oldVariable.GetVariableProperty(property).ToScalarExpression()
: SqlUtil.GetValueExpr(null);
var secondSelectColumn = newVariable.GetVariableProperty(property).ToScalarExpression() as WColumnReferenceExpression;
repeatFirstSelect.Add(SqlUtil.GetSelectScalarExpr(firstSelectColumn, aliasName));
repeatSecondSelect.Add(SqlUtil.GetSelectScalarExpr(secondSelectColumn, aliasName));
if (RepeatCondition.StartFromContext)
{
conditionVistorMap[(firstSelectColumn as WColumnReferenceExpression).Copy()] = aliasName;
}
else
{
conditionVistorMap[secondSelectColumn.Copy()] = aliasName;
}
}
}
}
if (RepeatCondition.EmitContext != null && RepeatCondition.EmitContext.VariableList.Count > 0)
{
var terminatedNewToOldSelectedVarMap = GetNewToOldSelectedVarMap(RepeatCondition.EmitContext);
if (!terminatedNewToOldSelectedVarMap.ContainsKey(RepeatContext.PivotVariable))
{
terminatedNewToOldSelectedVarMap[RepeatContext.PivotVariable] = RepeatCondition.EmitContext.VariableList.First();
}
foreach (var pair in terminatedNewToOldSelectedVarMap)
{
GremlinVariable newVariable = pair.Key;
GremlinVariable oldVariable = pair.Value;
foreach (var property in pair.Value.ProjectedProperties)
{
var aliasName = GenerateKey();
var firstSelectColumn = RepeatCondition.IsEmitContext
? oldVariable.GetVariableProperty(property).ToScalarExpression()
: SqlUtil.GetValueExpr(null);
var secondSelectColumn = newVariable.GetVariableProperty(property).ToScalarExpression() as WColumnReferenceExpression;
repeatFirstSelect.Add(SqlUtil.GetSelectScalarExpr(firstSelectColumn, aliasName));
repeatSecondSelect.Add(SqlUtil.GetSelectScalarExpr(secondSelectColumn, aliasName));
if (RepeatCondition.IsEmitContext)
{
conditionVistorMap[(firstSelectColumn as WColumnReferenceExpression).Copy()] = aliasName;
}
else
{
conditionVistorMap[secondSelectColumn.Copy()] = aliasName;
}
}
}
}
foreach (var property in ProjectedProperties)
{
if (property == GremlinKeyword.Path)
{
repeatFirstSelect.Add(SqlUtil.GetSelectScalarExpr(SqlUtil.GetValueExpr(null), GremlinKeyword.Path));
repeatSecondSelect.Add(SqlUtil.GetSelectScalarExpr(RepeatContext.ContextLocalPath.GetDefaultProjection().ToScalarExpression(), GremlinKeyword.Path));
continue;
}
WScalarExpression firstExpr = InputVariable.ProjectedProperties.Contains(property)
? InputVariable.GetVariableProperty(property).ToScalarExpression()
: SqlUtil.GetValueExpr(null);
WScalarExpression secondExpr = RepeatContext.PivotVariable.ProjectedProperties.Contains(property)
? RepeatContext.PivotVariable.GetVariableProperty(property).ToScalarExpression()
: SqlUtil.GetValueExpr(null);
repeatFirstSelect.Add(SqlUtil.GetSelectScalarExpr(firstExpr, property));
repeatSecondSelect.Add(SqlUtil.GetSelectScalarExpr(secondExpr, property));
}
WSelectQueryBlock firstQueryExpr = new WSelectQueryBlock();
foreach (var selectColumnExpr in repeatFirstSelect)
{
firstQueryExpr.SelectElements.Add(selectColumnExpr);
}
repeatQueryBlock = RepeatContext.ToSelectQueryBlock();
repeatQueryBlock.SelectElements.Clear();
foreach (var selectColumnExpr in repeatSecondSelect)
{
repeatQueryBlock.SelectElements.Add(selectColumnExpr);
}
//Replace N_0.id -> R_0.key_0, when N_0 is a outer variable
new ModifyColumnNameVisitor().Invoke(repeatQueryBlock, repeatVistorMap);
new ModifyColumnNameVisitor().Invoke(repeatConditionExpr, conditionVistorMap);
List <WScalarExpression> repeatParameters = new List <WScalarExpression>()
{
SqlUtil.GetScalarSubquery(SqlUtil.GetBinaryQueryExpr(firstQueryExpr, repeatQueryBlock)),
repeatConditionExpr
};
var tableRef = SqlUtil.GetFunctionTableReference(GremlinKeyword.func.Repeat, repeatParameters, GetVariableName());
return(SqlUtil.GetCrossApplyTableReference(tableRef));
}
private WMatchClause ConstructReversedMatchClause(WSelectQueryBlock node, WSqlTableContext context)
{
var result = new WMatchClause()
{
Paths = new List<WMatchPath>(),
};
foreach (var path in node.MatchClause.Paths)
{
var reversedEdgeNameList = new List<string>();
var nodeList = new List<Tuple<WSchemaObjectName, WEdgeColumnReferenceExpression>>();
var edgeList = path.PathEdgeList;
for (var i = 0; i < edgeList.Count; ++i)
{
var sourceTableName = edgeList[i].Item1.Identifiers.Last().Value;
var edgeName = edgeList[i].Item2.MultiPartIdentifier.Identifiers.Last().Value;
WTableReference sourceTable = context[sourceTableName];
var sourceTableObjectName =
(sourceTable as WNamedTableReference).TableObjectName.Identifiers.Last().Value;
reversedEdgeNameList.Add(sourceTableObjectName + "_" + edgeName + "Reversed");
}
var sinkIdentifier = path.Tail.Identifiers.Last();
for (var i = edgeList.Count - 1; i >= 0; --i)
{
var nodeName = new WSchemaObjectName()
{
Identifiers = new List<Identifier>
{
new Identifier()
{
Value = sinkIdentifier.Value,
QuoteType = sinkIdentifier.QuoteType,
}
},
};
var originalPath = edgeList[i].Item2;
var edgeCol = new WEdgeColumnReferenceExpression()
{
ColumnType = ColumnType.Regular,
Alias = originalPath.Alias,
MaxLength = originalPath.MaxLength,
MinLength = originalPath.MinLength,
AttributeValueDict = originalPath.AttributeValueDict,
MultiPartIdentifier = new WMultiPartIdentifier(new Identifier()
{
QuoteType = originalPath.MultiPartIdentifier.Identifiers.Last().QuoteType,
Value = reversedEdgeNameList[i],
}),
};
nodeList.Add(new Tuple<WSchemaObjectName, WEdgeColumnReferenceExpression>(nodeName, edgeCol));
sinkIdentifier = edgeList[i].Item1.Identifiers.Last();
}
result.Paths.Add(new WMatchPath
{
PathEdgeList = nodeList,
Tail = edgeList[0].Item1,
IsReversed = true,
});
}
return result;
}
/// <summary>
/// Marks the node table alias, if it has no outgoing edges in the graph pattern
/// and its node properties are never referenced or projected in the query.
/// Such node table aliases will not appear in the FROM clause in the translated
/// query, but only be materialized in adjacency lists, i.e., table-valued functions.
/// </summary>
/// <param name="query"></param>
/// <param name="graph"></param>
private void OptimizeTail(WSelectQueryBlock query, MatchGraph graph)
{
var visitor = new CheckTableReferenceVisitor();
foreach (var connectedSubGraph in graph.ConnectedSubGraphs)
{
var toRemove = connectedSubGraph.Nodes.Where(
node => node.Value.Neighbors.Count == 0 &&
!visitor.Invoke(query, node.Key, _context, _graphMetaData.ColumnsOfNodeTables)
)
.ToArray();
foreach (var item in toRemove)
{
connectedSubGraph.IsTailNode[item.Value] = true;
}
}
}
/// <summary>
/// If a table alias in the MATCH clause is defined in an upper-level context,
/// to be able to translate this MATCH clause, this table alias must be re-materialized
/// in the FROM clause of the current context and joined with the corresponding table
/// in the upper-level context.
/// </summary>
/// <param name="query">Select query</param>
/// <param name="nodes">A collection of node alias and match node instance</param>
private void RematerilizeExtrenalNodeTableReference(WSelectQueryBlock query, Dictionary<string, MatchNode> nodes)
{
var tableRefs = query.FromClause.TableReferences;
var tableSet = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
var newTableRefs = new List<WTableReference>();
for (int index = 0; index < tableRefs.Count; ++index)
{
var table = tableRefs[index] as WNamedTableReference;
if (table == null)
{
newTableRefs.Add(tableRefs[index]);
continue;
}
if (!nodes.ContainsKey(table.ExposedName.Value))
{
newTableRefs.Add(table);
}
else
{
tableSet.Add(table.ExposedName.Value);
}
}
query.FromClause = new WFromClause
{
TableReferences = newTableRefs,
};
WBooleanExpression whereCondiction = null;
foreach (var node in nodes.Where(node => !tableSet.Contains(node.Key)))
{
node.Value.External = true;
var newWhereCondition = new WBooleanComparisonExpression
{
ComparisonType = BooleanComparisonType.Equals,
FirstExpr = new WColumnReferenceExpression
{
MultiPartIdentifier = new WMultiPartIdentifier(
new Identifier { Value = node.Key },
new Identifier { Value = "GlobalNodeId" })
},
SecondExpr = new WColumnReferenceExpression
{
MultiPartIdentifier = new WMultiPartIdentifier(
new Identifier { Value = node.Value.RefAlias },
new Identifier { Value = "GlobalNodeId" })
},
};
whereCondiction = WBooleanBinaryExpression.Conjunction(whereCondiction, newWhereCondition);
}
if (whereCondiction != null)
{
if (query.WhereClause == null)
{
query.WhereClause = new WWhereClause { SearchCondition = whereCondiction };
}
else
{
if (query.WhereClause.SearchCondition == null)
{
query.WhereClause.SearchCondition = whereCondiction;
}
else
{
query.WhereClause.SearchCondition = new WBooleanBinaryExpression
{
BooleanExpressionType = BooleanBinaryExpressionType.And,
FirstExpr = new WBooleanParenthesisExpression
{
Expression = query.WhereClause.SearchCondition
},
SecondExpr = new WBooleanParenthesisExpression
{
Expression = whereCondiction
}
};
}
}
}
}
public override void Visit(WSelectQueryBlock node)
{
if (node.SelectElements == null || node.SelectElements.Count < 2)
{
throw new GraphViewException("Numbers of select elements mismatch.");
}
var sourceTableScalar = node.SelectElements[0] as WSelectScalarExpression;
if (sourceTableScalar == null)
throw new GraphViewException("Source node id should be a scalar expression.");
var sourceTableColumn = sourceTableScalar.SelectExpr as WColumnReferenceExpression;
if (sourceTableColumn == null)
throw new GraphViewException("Source node id column should be a column reference expression.");
var sourceTableName = sourceTableColumn.MultiPartIdentifier.Identifiers.Last().Value;
var sourceNodeIdExpr = new WColumnReferenceExpression();
foreach (var identifier in sourceTableColumn.MultiPartIdentifier.Identifiers)
sourceNodeIdExpr.Add(identifier);
sourceNodeIdExpr.AddIdentifier("GlobalNodeId");
if (node.SelectElements.Count < 2)
throw new GraphViewException("Source and Sink tables should be specified in select elements.");
if (node.GroupByClause != null)
{
throw new GraphViewException("GROUP BY clause is not allowed in INSERT EDGE statement.");
}
var collectVarVisitor = new CollectVariableVisitor();
var context = collectVarVisitor.Invoke(node);
WColumnReferenceExpression sinkNodeIdExpr = null;
for (var index = 1; index < node.SelectElements.Count; ++index)
{
var element = node.SelectElements[index] as WSelectScalarExpression;
if (element == null)
throw new GraphViewException("Edge property should be a scalar expression.");
//sink table
if (index == 1)
{
var sinkTableColumn = element.SelectExpr as WColumnReferenceExpression;
if (sinkTableColumn == null)
throw new GraphViewException("Sink node id column should be a column reference expression.");
var sinkTableName = sinkTableColumn.MultiPartIdentifier.Identifiers.Last().Value;
_sinkTable = context[sinkTableName];
sinkNodeIdExpr = new WColumnReferenceExpression();
foreach (var identifier in sinkTableColumn.MultiPartIdentifier.Identifiers)
sinkNodeIdExpr.Add(identifier);
sinkNodeIdExpr.AddIdentifier("GlobalNodeId");
}
else
{
_edgeProperties.Add(element.SelectExpr);
}
}
var sourceTable = context[sourceTableName] as WNamedTableReference;
if (sourceTable == null)
{
throw new GraphViewException("Source table of INSERT EDGE statement should be a named table reference.");
}
var sourceNodeId = new WSelectScalarExpression
{
SelectExpr = sourceNodeIdExpr,
ColumnName = "src",
};
var sinkNodeId = new WSelectScalarExpression
{
SelectExpr = sinkNodeIdExpr,
ColumnName = "sink"
};
var elements = new List<WSelectElement>
{
sourceNodeId,
sinkNodeId
};
var result = new WCommonTableExpression
{
ExpressionName = new Identifier {Value = _tempTableName},
QueryExpression = new WSelectQueryBlock
{
FromClause = node.FromClause,
WhereClause = new WWhereClause
{
SearchCondition = node.WhereClause.SearchCondition
},
HavingClause = node.HavingClause,
OrderByClause = node.OrderByClause,
TopRowFilter = node.TopRowFilter,
UniqueRowFilter = node.UniqueRowFilter,
SelectElements = elements,
MatchClause = node.MatchClause
}
};
_result = result;
}
/// <summary>
/// If paths is referenced in the MATCH clause, checks the SELECT elements to decide whether the
/// paths informaion is needed to be displayed. If PathAlias.* occurs in the SELECT elements,
/// sets the corresponding bool value in MatchPath, and replaces this element with
/// an scalar function to display readable path information
/// </summary>
/// <param name="query">Select query</param>
/// <param name="pathDictionary">A collection of path alias and match path instance</param>
private void TransformPathInfoDisplaySelectElement(WSelectQueryBlock query,
Dictionary<string, MatchPath> pathDictionary)
{
if (pathDictionary!=null && pathDictionary.Any())
{
List<WSelectElement> newSelectElements = new List<WSelectElement>();
foreach (var selectElement in query.SelectElements)
{
var starElement = selectElement as WSelectStarExpression;
if (starElement != null && starElement.Qulifier != null)
{
var colName = starElement.Qulifier.Identifiers[starElement.Qulifier.Count - 1].Value;
MatchPath path;
if (pathDictionary.TryGetValue(colName, out path))
{
path.ReferencePathInfo = true;
string schema = path.BindNodeTableObjName.SchemaIdentifier.Value;
string tableName = path.BindNodeTableObjName.BaseIdentifier.Value;
string pathName = path.EdgeColumn.MultiPartIdentifier.Identifiers.Last().Value;
var parameters = new List<WScalarExpression>
{
new WColumnReferenceExpression
{
MultiPartIdentifier =
new WMultiPartIdentifier(new Identifier() {Value = path.EdgeAlias},
new Identifier() {Value = "PathMessage"})
},
};
if (
_graphMetaData.NodeViewMapping.ContainsKey(
WNamedTableReference.SchemaNameToTuple(path.SinkNode.NodeTableObjectName)))
{
parameters.Add(new WColumnReferenceExpression
{
MultiPartIdentifier =
new WMultiPartIdentifier(new Identifier() { Value = path.SinkNode.RefAlias },
new Identifier() { Value = "_NodeType" })
});
parameters.Add(new WColumnReferenceExpression
{
MultiPartIdentifier =
new WMultiPartIdentifier(new Identifier() { Value = path.SinkNode.RefAlias },
new Identifier() { Value = "_NodeId" })
});
}
else
{
parameters.Add(new WValueExpression
{
Value = path.SinkNode.NodeTableObjectName.BaseIdentifier.Value,
SingleQuoted = true
});
string sinkNodeIdName =
_graphMetaData.ColumnsOfNodeTables[
WNamedTableReference.SchemaNameToTuple(path.SinkNode.NodeTableObjectName)]
.FirstOrDefault(e => e.Value.Role == WNodeTableColumnRole.NodeId).Key;
if (string.IsNullOrEmpty(sinkNodeIdName))
parameters.Add(new WValueExpression { Value = "null" });
else
{
parameters.Add(new WColumnReferenceExpression
{
MultiPartIdentifier =
new WMultiPartIdentifier(new Identifier() { Value = path.SinkNode.RefAlias },
new Identifier() { Value = sinkNodeIdName })
});
}
}
newSelectElements.Add(new WSelectScalarExpression
{
ColumnName = path.EdgeAlias + "_PathInfo",
SelectExpr = new WFunctionCall
{
CallTarget = new WMultiPartIdentifierCallTarget
{
Identifiers = new WMultiPartIdentifier(new Identifier { Value = "dbo" })
},
FunctionName = new Identifier { Value = string.Format("{0}_{1}_{2}_PathMessageDecoder", schema, tableName, pathName) },
Parameters = parameters
}
});
continue;
}
}
newSelectElements.Add(selectElement);
}
query.SelectElements = newSelectElements;
}
}
/// <summary>
/// The entry of the optimizer, activated when visting each Select Query Block
/// </summary>
/// <param name="node"></param>
public override void Visit(WSelectQueryBlock node)
{
var checkVarVisitor = new CollectVariableVisitor();
var currentContext = checkVarVisitor.Invoke(node.FromClause, _columnsOfNodeTables.Keys);
currentContext.UpperLevel = _context;
_context = currentContext;
base.Visit(node);
_statisticsCalculator.Context = _context;
CheckValidity(node);
var graph = ConstructGraph(node);
//ChangeSelectStarExpression(node, graph);
if (graph != null)
{
OptimizeTail(node, graph);
EstimateRows(node, graph);
EstimateAverageDegree(graph);
var components = new List<MatchComponent>();
foreach (var subGraph in graph.ConnectedSubGraphs)
{
components.Add(ConstructComponent(subGraph));
#if DEBUG
foreach (var matchNode in subGraph.Nodes.Values)
{
Trace.WriteLine(matchNode.NodeAlias);
Trace.WriteLine(string.Format(" RowCount:{0}", matchNode.TableRowCount));
Trace.WriteLine(string.Format(" EstiRow:{0}", matchNode.EstimatedRows));
}
#endif
}
UpdateQuery(node, components);
#if DEBUG
Trace.WriteLine(string.Format("Rows:{0}", components[0].Size));
Trace.WriteLine(string.Format("Cost:{0}", components[0].Cost));
Trace.WriteLine(string.Format("Estimated Rows:{0}", components[0].EstimateSize));
#endif
node.MatchClause = null;
}
_context = _context.UpperLevel;
}
/// <summary>
/// Update FROM clause, adds DOWNSIZE predicates in the corresponding join conditions,
/// and add corresponding predicates on the spilt nodes in the WHERE clause using
/// optimal component of each connected sub-graph.
/// </summary>
/// <param name="node">The SELECT statement</param>
/// <param name="components">The optimal components of each fully-connected graph</param>
private void UpdateQuery(WSelectQueryBlock node, List<MatchComponent> components)
{
// Removes schema name in SELECT clause and all column references.
var removeSchemaVisitor = new RemoveSchemanameInIdentifersVisitor();
removeSchemaVisitor.Visit(node);
foreach (var component in components)
{
//// Cross apply the unmaterilized edges which point to the optimized tail nodes
//Dictionary<MatchNode, MatchEdge> UnMatEdgeJoinDict = new Dictionary<MatchNode, MatchEdge>();
//foreach (var unMatEdge in component.EdgeMaterilizedDict.Where(e => !e.Value).Select(e => e.Key))
//{
// component.TableRef = component.SpanTableRef(component.TableRef,
// unMatEdge, component.GetNodeRefName(unMatEdge.SourceNode), _graphMetaData);
// MatchEdge joinEdge;
// if (UnMatEdgeJoinDict.TryGetValue(unMatEdge.SinkNode, out joinEdge))
// {
// if (!string.IsNullOrEmpty(newWhereString))
// newWhereString += " AND ";
// newWhereString += string.Format("{0}.Sink = {1}.Sink", joinEdge.EdgeAlias, unMatEdge.EdgeAlias);
// }
// else
// {
// UnMatEdgeJoinDict[unMatEdge.SinkNode] = unMatEdge;
// }
//}
// Updates from clause
node.FromClause.TableReferences.Add(component.TableRef);
}
WBooleanExpression attachWhereCondition = null;
foreach (var component in components)
{
attachWhereCondition = WBooleanBinaryExpression.Conjunction(attachWhereCondition,
component.WhereCondition);
}
if (attachWhereCondition != null)
{
if (node.WhereClause != null && node.WhereClause.SearchCondition != null)
node.WhereClause.SearchCondition = new WBooleanParenthesisExpression
{
Expression = node.WhereClause.SearchCondition
};
else
{
node.WhereClause = new WWhereClause();
}
node.WhereClause.SearchCondition = WBooleanBinaryExpression.Conjunction(attachWhereCondition,
node.WhereClause.SearchCondition);
}
}
public override void Visit(WSelectQueryBlock node)
{
UpdateMapping(node);
}
/// <summary>
/// The entry point of the optimizer, activated when visting each SELECT query block.
/// </summary>
/// <param name="node">The SELECT query block</param>
public override void Visit(WSelectQueryBlock node)
{
var checkVarVisitor = new CollectVariableVisitor();
var currentContext = checkVarVisitor.Invoke(node.FromClause, _graphMetaData.ColumnsOfNodeTables.Keys);
currentContext.ParentContext = _context;
_context = currentContext;
base.Visit(node);
CheckValidity(node);
var graph = ConstructGraph(node);
//ChangeSelectStarExpression(node, graph);
if (graph != null)
{
//OptimizeTail(node, graph);
AttachPredicates(node.WhereClause,graph);
EstimateRows(graph);
RetrieveStatistics(graph);
var components = new List<MatchComponent>();
foreach (var subGraph in graph.ConnectedSubGraphs)
{
components.Add(ConstructComponent(subGraph, graph.ReversedEdgeDict, graph.SourceNodeStatisticsDict));
#if DEBUG
foreach (var matchNode in subGraph.Nodes.Values)
{
Trace.WriteLine(matchNode.NodeAlias);
Trace.WriteLine(string.Format(" RowCount:{0}", matchNode.TableRowCount));
Trace.WriteLine(string.Format(" EstiRow:{0}", matchNode.EstimatedRows));
}
#endif
}
UpdateQuery(node, components);
#if DEBUG
Trace.WriteLine(string.Format("Rows:{0}", components[0].Cardinality));
Trace.WriteLine(string.Format("Cost:{0}", components[0].Cost));
Trace.WriteLine(string.Format("Estimated Rows:{0}", components[0].SqlEstimatedSize));
#endif
node.MatchClause = null;
}
_context = _context.ParentContext;
}
public virtual void Visit(WSelectQueryBlock node)
{
node.AcceptChildren(this);
}
private WSelectQueryExpression ParseSelectQueryStatement(QueryExpression queryExpr)
{
if (queryExpr == null)
{
return null;
}
switch (queryExpr.GetType().Name)
{
case "BinaryQueryExpression":
{
var bqe = queryExpr as BinaryQueryExpression;
var pQueryExpr = new WBinaryQueryExpression
{
All = bqe.All,
FirstQueryExpr = ParseSelectQueryStatement(bqe.FirstQueryExpression),
SecondQueryExpr = ParseSelectQueryStatement(bqe.SecondQueryExpression),
FirstTokenIndex = bqe.FirstTokenIndex,
LastTokenIndex = bqe.LastTokenIndex
};
//pQueryExpr.OrderByExpr = parseOrderbyExpr(bqe.OrderByClause);
return pQueryExpr;
}
case "QueryParenthesisExpression":
{
var qpe = queryExpr as QueryParenthesisExpression;
var pQueryExpr = new WQueryParenthesisExpression
{
QueryExpr = ParseSelectQueryStatement(qpe.QueryExpression),
FirstTokenIndex = qpe.FirstTokenIndex,
LastTokenIndex = qpe.LastTokenIndex
};
//pQueryExpr.OrderByExpr = parseOrderbyExpr(qpe.OrderByClause);
return pQueryExpr;
}
case "QuerySpecification":
{
var qs = queryExpr as QuerySpecification;
var pQueryExpr = new WSelectQueryBlock
{
FirstTokenIndex = qs.FirstTokenIndex,
LastTokenIndex = qs.LastTokenIndex,
SelectElements = new List<WSelectElement>(qs.SelectElements.Count),
};
//
// SELECT clause
//
foreach (var wsel in qs.SelectElements.Select(ParseSelectElement).Where(wsel => wsel != null))
{
pQueryExpr.SelectElements.Add(wsel);
}
//
// Top row filter
//
if (qs.TopRowFilter != null)
{
pQueryExpr.TopRowFilter = new WTopRowFilter
{
Percent = qs.TopRowFilter.Percent,
WithTies = qs.TopRowFilter.WithTies,
Expression = ParseScalarExpression(qs.TopRowFilter.Expression),
FirstTokenIndex = qs.TopRowFilter.FirstTokenIndex,
LastTokenIndex = qs.TopRowFilter.LastTokenIndex
};
}
pQueryExpr.UniqueRowFilter = qs.UniqueRowFilter;
//
// FROM clause
//
if (qs.FromClause != null && qs.FromClause.TableReferences != null)
{
pQueryExpr.FromClause.FirstTokenIndex = qs.FromClause.FirstTokenIndex;
pQueryExpr.FromClause.LastTokenIndex = qs.FromClause.LastTokenIndex;
pQueryExpr.FromClause.TableReferences = new List<WTableReference>(qs.FromClause.TableReferences.Count);
foreach (var pref in qs.FromClause.TableReferences.Select(ParseTableReference).Where(pref => pref != null))
{
pQueryExpr.FromClause.TableReferences.Add(pref);
}
}
//
// WHERE clause
//
if (qs.WhereClause != null && qs.WhereClause.SearchCondition != null)
{
pQueryExpr.WhereClause.FirstTokenIndex = qs.WhereClause.FirstTokenIndex;
pQueryExpr.WhereClause.LastTokenIndex = qs.WhereClause.LastTokenIndex;
pQueryExpr.WhereClause.SearchCondition = ParseBooleanExpression(qs.WhereClause.SearchCondition);
}
// GROUP-BY clause
if (qs.GroupByClause != null)
{
pQueryExpr.GroupByClause = ParseGroupbyClause(qs.GroupByClause);
}
// Having clause
if (qs.HavingClause != null)
{
pQueryExpr.HavingClause = new WHavingClause
{
SearchCondition = ParseBooleanExpression(qs.HavingClause.SearchCondition),
FirstTokenIndex = qs.HavingClause.FirstTokenIndex,
LastTokenIndex = qs.HavingClause.LastTokenIndex
};
}
//
// ORDER-BY clause
//
if (qs.OrderByClause != null)
{
pQueryExpr.OrderByClause = ParseOrderbyClause(qs.OrderByClause);
}
return pQueryExpr;
}
default:
return null;
}
}
/// <summary>
/// Update FROM clause, adds DOWNSIZE predicates in the corresponding join conditions,
/// and add corresponding predicates on the spilt nodes in the WHERE clause using
/// optimal component of each connected sub-graph.
/// </summary>
/// <param name="node">The SELECT statement</param>
/// <param name="components">The optimal components of each fully-connected graph</param>
private void UpdateQuery(WSelectQueryBlock node, List<MatchComponent> components)
{
// Removes schema name in SELECT clause and all column references.
var removeSchemaVisitor = new RemoveSchemanameInIdentifersVisitor();
removeSchemaVisitor.Visit(node);
string newWhereString = "";
foreach (var component in components)
{
// Adds predicates for split nodes
var component1 = component;
foreach (
var compNode in
component.MaterializedNodeSplitCount.Where(
e => e.Value > 0 && e.Key.Predicates != null && e.Key.Predicates.Any()))
{
var matchNode = compNode.Key;
WBooleanExpression newExpression =
matchNode.Predicates.Aggregate<WBooleanExpression, WBooleanExpression>(null,
WBooleanBinaryExpression.Conjunction);
string predicateString = newExpression.ToString();
var nodeCount = component1.MaterializedNodeSplitCount[matchNode];
while (nodeCount > 0)
{
newWhereString += " AND ";
string tempStr = predicateString.Replace(string.Format("[{0}]", matchNode.RefAlias.ToUpper()),
string.Format("[{0}_{1}]", matchNode.RefAlias.ToUpper(), nodeCount));
tempStr = tempStr.Replace(string.Format("[{0}]", matchNode.RefAlias.ToLower()),
string.Format("[{0}_{1}]", matchNode.RefAlias.ToLower(), nodeCount));
newWhereString += tempStr;
nodeCount--;
}
}
// Cross apply the unmaterilized edges which point to the optimized tail nodes
Dictionary<MatchNode,MatchEdge> UnMatEdgeJoinDict = new Dictionary<MatchNode, MatchEdge>();
foreach (var unMatEdge in component.EdgeMaterilizedDict.Where(e => !e.Value).Select(e=>e.Key))
{
component.TableRef = component.SpanTableRef(component.TableRef,
unMatEdge, component.GetNodeRefName(unMatEdge.SourceNode),_graphMetaData);
MatchEdge joinEdge;
if (UnMatEdgeJoinDict.TryGetValue(unMatEdge.SinkNode, out joinEdge))
{
if (!string.IsNullOrEmpty(newWhereString))
newWhereString += " AND ";
newWhereString += string.Format("{0}.Sink = {1}.Sink", joinEdge.EdgeAlias, unMatEdge.EdgeAlias);
}
else
{
UnMatEdgeJoinDict[unMatEdge.SinkNode] = unMatEdge;
}
}
// Updates from clause
node.FromClause.TableReferences.Add(component.TableRef);
}
if (!string.IsNullOrEmpty(newWhereString))
{
if (node.WhereClause!=null && node.WhereClause.SearchCondition!=null)
node.WhereClause.SearchCondition = new WBooleanParenthesisExpression
{
Expression = node.WhereClause.SearchCondition
};
else
{
node.WhereClause = new WWhereClause();
}
node.WhereClause.GhostString = newWhereString;
}
}
/// <summary>
/// Update from clause in the query using optimal component of each connected sub-graph
/// </summary>
/// <param name="node"></param>
/// <param name="components"></param>
private void UpdateQuery(WSelectQueryBlock node, List<MatchComponent> components)
{
string newWhereString = "";
foreach (var component in components)
{
// Add down size predicates
foreach (var joinTableTuple in component.FatherListofDownSizeTable)
{
var joinTable = joinTableTuple.Item1;
joinTable.JoinCondition = WBooleanBinaryExpression.Conjunction(joinTable.JoinCondition,
new WBooleanComparisonExpression
{
ComparisonType = BooleanComparisonType.Equals,
FirstExpr = new WFunctionCall
{
CallTarget = new WMultiPartIdentifierCallTarget
{
Identifiers = new WMultiPartIdentifier(new Identifier { Value = "dbo" })
},
FunctionName = new Identifier { Value = "DownSizeFunction" },
Parameters = new List<WScalarExpression>
{
new WColumnReferenceExpression
{
MultiPartIdentifier = new WMultiPartIdentifier
{
Identifiers = new List<Identifier>
{
new Identifier{Value = joinTableTuple.Item2},
new Identifier {Value = "LocalNodeid"}
}
}
}
}
},
SecondExpr = new WValueExpression("1", false)
});
}
// Update from clause
node.FromClause.TableReferences.Add(component.TableRef);
// Add predicates for split nodes
var component1 = component;
foreach (
var compNode in
component.MaterializedNodeSplitCount.Where(
e => e.Value>0 && e.Key.Predicates != null && e.Key.Predicates.Any()))
{
var matchNode = compNode.Key;
WBooleanExpression newExpression = null;
foreach (var predicate in matchNode.Predicates)
{
newExpression = WBooleanBinaryExpression.Conjunction(newExpression, predicate);
}
string predicateString = newExpression.ToString().ToLower();
var nodeCount = component1.MaterializedNodeSplitCount[matchNode];
while (nodeCount > 0)
{
newWhereString += " AND ";
newWhereString += predicateString.Replace(string.Format("[{0}]", matchNode.RefAlias.ToLower()),
string.Format("[{0}_{1}]", matchNode.RefAlias, nodeCount));
nodeCount--;
}
}
}
if (newWhereString.Any())
{
node.WhereClause.SearchCondition = new WBooleanParenthesisExpression
{
Expression = node.WhereClause.SearchCondition
};
node.WhereClause.GhostString = newWhereString;
}
var visitor2 = new DeleteSchemanameInSelectVisitor();
visitor2.Invoke(node);
}
internal bool HasAggregateFunctionInTheRepeatSelectQuery(WSelectQueryBlock repeatSelectQuery)
{
AggregateFunctionCountVisitor aggregateCountVisitor = new AggregateFunctionCountVisitor();
return(aggregateCountVisitor.Invoke(repeatSelectQuery) > 0);
}
/// <summary>
/// Constructs the graph pattern specified by the MATCH clause.
/// The graph pattern may consist of multiple fully-connected sub-graphs.
/// </summary>
/// <param name="query">The SELECT query block</param>
/// <returns>A graph object contains all the connected componeents</returns>
private MatchGraph ConstructGraph(WSelectQueryBlock query)
{
if (query == null || query.MatchClause == null)
return null;
var columnsOfNodeTables = _graphMetaData.ColumnsOfNodeTables;
var nodeViewMapping = _graphMetaData.NodeViewMapping;
var unionFind = new UnionFind();
var edgeColumnToAliasesDict = new Dictionary<string, List<string>>(StringComparer.OrdinalIgnoreCase);
var pathDictionary = new Dictionary<string, MatchPath>(StringComparer.OrdinalIgnoreCase);
var reversedEdgeDict = new Dictionary<string, MatchEdge>();
var matchClause = query.MatchClause;
var nodes = new Dictionary<string, MatchNode>(StringComparer.OrdinalIgnoreCase);
var connectedSubGraphs = new List<ConnectedComponent>();
var subGrpahMap = new Dictionary<string, ConnectedComponent>(StringComparer.OrdinalIgnoreCase);
var parent = new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
unionFind.Parent = parent;
// Constructs the graph pattern specified by the path expressions in the MATCH clause
foreach (var path in matchClause.Paths)
{
var index = 0;
MatchEdge preEdge = null;
for (var count = path.PathEdgeList.Count; index < count; ++index)
{
var currentNodeTableRef = path.PathEdgeList[index].Item1;
var currentEdgeColumnRef = path.PathEdgeList[index].Item2;
var currentNodeExposedName = currentNodeTableRef.BaseIdentifier.Value;
var nextNodeTableRef = index != count - 1
? path.PathEdgeList[index + 1].Item1
: path.Tail;
var nextNodeExposedName = nextNodeTableRef.BaseIdentifier.Value;
var patternNode = nodes.GetOrCreate(currentNodeExposedName);
if (patternNode.NodeAlias == null)
{
patternNode.NodeAlias = currentNodeExposedName;
patternNode.Neighbors = new List<MatchEdge>();
patternNode.External = false;
var nodeTable = _context[currentNodeExposedName] as WNamedTableReference;
if (nodeTable != null)
{
patternNode.NodeTableObjectName = nodeTable.TableObjectName;
if (patternNode.NodeTableObjectName.SchemaIdentifier == null)
patternNode.NodeTableObjectName.Identifiers.Insert(0, new Identifier {Value = "dbo"});
}
}
Identifier edgeIdentifier = currentEdgeColumnRef.MultiPartIdentifier.Identifiers.Last();
string schema = patternNode.NodeTableObjectName.SchemaIdentifier.Value.ToLower();
string nodeTableName = patternNode.NodeTableObjectName.BaseIdentifier.Value;
string bindTableName =
_context.EdgeNodeBinding[
new Tuple<string, string>(nodeTableName.ToLower(), edgeIdentifier.Value.ToLower())].ToLower();
var bindNodeTableObjName = new WSchemaObjectName(
new Identifier {Value = schema},
new Identifier {Value = bindTableName}
);
var edgeColumn =
columnsOfNodeTables[
WNamedTableReference.SchemaNameToTuple(bindNodeTableObjName)][
currentEdgeColumnRef.MultiPartIdentifier.Identifiers.Last().Value];
string edgeAlias = currentEdgeColumnRef.Alias;
//string revEdgeAlias = edgeAlias;
bool isReversed = path.IsReversed || edgeColumn.EdgeInfo.IsReversedEdge;
string currentRevEdgeName = null;
// get original edge name
var currentEdgeName = currentEdgeColumnRef.MultiPartIdentifier.Identifiers.Last().Value;
var originalSourceName = isReversed ?
(_context[nextNodeExposedName] as WNamedTableReference).TableObjectName.BaseIdentifier.Value
: (_context[currentNodeExposedName] as WNamedTableReference).TableObjectName.BaseIdentifier.Value;
if (isReversed)
{
var i = currentEdgeName.IndexOf(originalSourceName, StringComparison.OrdinalIgnoreCase) +
originalSourceName.Length;
currentRevEdgeName = currentEdgeName.Substring(i + 1,
currentEdgeName.Length - "Reversed".Length - i - 1);
}
else
{
var srcTuple = WNamedTableReference.SchemaNameToTuple(patternNode.NodeTableObjectName);
// [nodeView]-[edge]->[node/nodeView]
if (edgeColumn.Role == WNodeTableColumnRole.Edge && nodeViewMapping.ContainsKey(srcTuple))
{
var physicalNodeName =
_context.EdgeNodeBinding[new Tuple<string, string>(srcTuple.Item2, currentEdgeName.ToLower())];
currentRevEdgeName = physicalNodeName + "_" + currentEdgeName + "Reversed";
}
else
{
currentRevEdgeName = originalSourceName + "_" + currentEdgeName + "Reversed";
}
}
if (edgeAlias == null)
{
edgeAlias = !isReversed
? string.Format("{0}_{1}_{2}", currentNodeExposedName, currentEdgeName, nextNodeExposedName)
: string.Format("{0}_{1}_{2}", nextNodeExposedName, currentRevEdgeName, currentNodeExposedName);
//when the current edge is a reversed edge, the key should still be the original edge name
//e.g.: TestDeleteEdgeWithTableAlias
var edgeNameKey = isReversed ? currentRevEdgeName : currentEdgeName;
if (edgeColumnToAliasesDict.ContainsKey(edgeNameKey))
{
edgeColumnToAliasesDict[edgeNameKey].Add(edgeAlias);
}
else
{
edgeColumnToAliasesDict.Add(edgeNameKey, new List<string> { edgeAlias });
}
}
MatchEdge edge, revEdge;
if (currentEdgeColumnRef.MinLength == 1 && currentEdgeColumnRef.MaxLength == 1)
{
var isEdgeView = edgeColumn.Role == WNodeTableColumnRole.EdgeView;
var hasRevEdge = edgeColumn.EdgeInfo.HasReversedEdge;
edge = new MatchEdge
{
IsEdgeView = isEdgeView,
IsReversedEdge = false,
HasReversedEdge = hasRevEdge,
SourceNode = patternNode,
EdgeColumn = currentEdgeColumnRef,
EdgeAlias = edgeAlias,
BindNodeTableObjName = bindNodeTableObjName,
};
_context.AddEdgeReference(edge);
if (hasRevEdge)
{
revEdge = new MatchEdge
{
IsEdgeView = isEdgeView,
IsReversedEdge = true,
SinkNode = patternNode,
EdgeColumn = new WEdgeColumnReferenceExpression()
{
ColumnType = currentEdgeColumnRef.ColumnType,
Alias = currentEdgeColumnRef.Alias,
MaxLength = currentEdgeColumnRef.MaxLength,
MinLength = currentEdgeColumnRef.MinLength,
AttributeValueDict = currentEdgeColumnRef.AttributeValueDict,
MultiPartIdentifier = new WMultiPartIdentifier(new Identifier()
{
QuoteType = currentEdgeColumnRef.MultiPartIdentifier.Identifiers.Last().QuoteType,
Value = currentRevEdgeName,
}),
},
EdgeAlias = edgeAlias,
//EdgeAlias = revEdgeAlias,
};
reversedEdgeDict[edge.EdgeAlias] = revEdge;
}
}
else
{
MatchPath matchPath = new MatchPath
{
SourceNode = patternNode,
EdgeColumn = currentEdgeColumnRef,
EdgeAlias = edgeAlias,
BindNodeTableObjName =
new WSchemaObjectName(
new Identifier {Value = schema},
new Identifier {Value = bindTableName}
),
MinLength = currentEdgeColumnRef.MinLength,
MaxLength = currentEdgeColumnRef.MaxLength,
ReferencePathInfo = false,
AttributeValueDict = currentEdgeColumnRef.AttributeValueDict
};
_context.AddEdgeReference(matchPath);
pathDictionary[edgeAlias] = matchPath;
edge = matchPath;
}
if (preEdge != null)
{
preEdge.SinkNode = patternNode;
if (preEdge.HasReversedEdge)
{
//var preSourceNode = preEdge.SourceNode;
var preEdgeBindNodeTableObjName = preEdge.BindNodeTableObjName;
var preEdgeColName = preEdge.EdgeColumn.MultiPartIdentifier.Identifiers.Last().Value;
var preEdgeColumn =
columnsOfNodeTables[
WNamedTableReference.SchemaNameToTuple(preEdgeBindNodeTableObjName)][
preEdgeColName];
var isEdgeView = preEdgeColumn.Role == WNodeTableColumnRole.EdgeView;
var isNodeView =
_graphMetaData.NodeViewMapping.ContainsKey(
WNamedTableReference.SchemaNameToTuple(patternNode.NodeTableObjectName));
reversedEdgeDict[preEdge.EdgeAlias].SourceNode = patternNode;
// [node/nodeView]-[edgeView]->[node/nodeView]
if (isEdgeView)
{
reversedEdgeDict[preEdge.EdgeAlias].BindNodeTableObjName = preEdgeBindNodeTableObjName;
}
// [node/nodeView]-[edge]->[nodeView]
else if (!isEdgeView && isNodeView)
{
reversedEdgeDict[preEdge.EdgeAlias].BindNodeTableObjName = new WSchemaObjectName(
new Identifier { Value = "dbo" },
new Identifier { Value = preEdgeColumn.EdgeInfo.SinkNodes.First() }
);
}
else
{
reversedEdgeDict[preEdge.EdgeAlias].BindNodeTableObjName = new WSchemaObjectName(
new Identifier { Value = schema },
new Identifier { Value = bindTableName }
);
}
}
}
preEdge = edge;
if (!parent.ContainsKey(currentNodeExposedName))
parent[currentNodeExposedName] = currentNodeExposedName;
if (!parent.ContainsKey(nextNodeExposedName))
parent[nextNodeExposedName] = nextNodeExposedName;
unionFind.Union(currentNodeExposedName, nextNodeExposedName);
patternNode.Neighbors.Add(edge);
}
var tailExposedName = path.Tail.BaseIdentifier.Value;
var tailNode = nodes.GetOrCreate(tailExposedName);
if (tailNode.NodeAlias == null)
{
tailNode.NodeAlias = tailExposedName;
tailNode.Neighbors = new List<MatchEdge>();
var nodeTable = _context[tailExposedName] as WNamedTableReference;
if (nodeTable != null)
{
tailNode.NodeTableObjectName = nodeTable.TableObjectName;
if (tailNode.NodeTableObjectName.SchemaIdentifier == null)
tailNode.NodeTableObjectName.Identifiers.Insert(0, new Identifier {Value = "dbo"});
}
}
if (preEdge != null)
{
preEdge.SinkNode = tailNode;
if (preEdge.HasReversedEdge)
{
var schema = tailNode.NodeTableObjectName.SchemaIdentifier.Value.ToLower();
var nodeTableName = tailNode.NodeTableObjectName.BaseIdentifier.Value;
//var preSourceNode = preEdge.SourceNode;
var preEdgeBindNodeTableObjName = preEdge.BindNodeTableObjName;
var preEdgeColName = preEdge.EdgeColumn.MultiPartIdentifier.Identifiers.Last().Value;
var preEdgeColumn =
columnsOfNodeTables[
WNamedTableReference.SchemaNameToTuple(preEdgeBindNodeTableObjName)][
preEdgeColName];
var isEdgeView = preEdgeColumn.Role == WNodeTableColumnRole.EdgeView;
var isNodeView =
_graphMetaData.NodeViewMapping.ContainsKey(
WNamedTableReference.SchemaNameToTuple(tailNode.NodeTableObjectName));
reversedEdgeDict[preEdge.EdgeAlias].SourceNode = tailNode;
// [node/nodeView]-[edgeView]->[node/nodeView]
if (isEdgeView)
{
reversedEdgeDict[preEdge.EdgeAlias].BindNodeTableObjName = preEdgeBindNodeTableObjName;
}
// [node/nodeView]-[edge]->[nodeView]
else if (!isEdgeView && isNodeView)
{
reversedEdgeDict[preEdge.EdgeAlias].BindNodeTableObjName = new WSchemaObjectName(
new Identifier { Value = "dbo" },
new Identifier { Value = preEdgeColumn.EdgeInfo.SinkNodes.First() }
);
}
else
{
reversedEdgeDict[preEdge.EdgeAlias].BindNodeTableObjName = new WSchemaObjectName(
new Identifier { Value = schema },
new Identifier { Value = nodeTableName.ToLower() }
);
}
}
}
}
// Puts nodes into subgraphs
foreach (var node in nodes)
{
string root = unionFind.Find(node.Key);
if (!subGrpahMap.ContainsKey(root))
{
var subGraph = new ConnectedComponent();
subGraph.Nodes[node.Key] = node.Value;
foreach (var edge in node.Value.Neighbors)
{
subGraph.Edges[edge.EdgeAlias] = edge;
}
subGrpahMap[root] = subGraph;
connectedSubGraphs.Add(subGraph);
subGraph.IsTailNode[node.Value] = false;
}
else
{
var subGraph = subGrpahMap[root];
subGraph.Nodes[node.Key] = node.Value;
foreach (var edge in node.Value.Neighbors)
{
subGraph.Edges[edge.EdgeAlias] = edge;
}
subGraph.IsTailNode[node.Value] = false;
}
}
var graph = new MatchGraph
{
ReversedEdgeDict = reversedEdgeDict,
ConnectedSubGraphs = connectedSubGraphs,
SourceNodeStatisticsDict = new Dictionary<Tuple<string, bool>, Statistics>(),
};
unionFind.Parent = null;
// When an edge in the MATCH clause is not associated with an alias,
// assigns to it a default alias: sourceAlias_EdgeColumnName_sinkAlias.
// Also rewrites edge attributes anywhere in the query that can be bound to this default alias.
var replaceTableRefVisitor = new ReplaceEdgeReferenceVisitor();
replaceTableRefVisitor.Invoke(query, edgeColumnToAliasesDict);
// Rematerializes node tables in the MATCH clause which are defined in the upper-level context
// and join them with the upper-level table references.
RematerilizeExtrenalNodeTableReference(query, nodes);
// Transforms the path reference in the SELECT elements into a
// scalar function to display path information.
TransformPathInfoDisplaySelectElement(query, pathDictionary);
return graph;
}
/// <summary>
/// Replaces the SELECT * expression with all visible columns
/// </summary>
/// <param name="node"></param>
/// <param name="graph"></param>
private void ChangeSelectStarExpression(WSelectQueryBlock node, MatchGraph graph)
{
var newSelectElements = new List<WSelectElement>();
Dictionary<string, List<WSelectElement>> starReplacement = null;
foreach (var element in node.SelectElements)
{
var starElement = element as WSelectStarExpression;
if (starElement != null)
{
if (starReplacement == null)
{
starReplacement =
new Dictionary<string, List<WSelectElement>>(StringComparer.OrdinalIgnoreCase);
// Fetch table in order
foreach (var table in _context.NodeTableDictionary)
{
var alias = table.Key;
var namedTable = table.Value as WNamedTableReference;
if (namedTable != null)
{
foreach (
var column in
_graphMetaData.ColumnsOfNodeTables[
WNamedTableReference.SchemaNameToTuple(namedTable.TableObjectName)].Where(
e => e.Value.Role != WNodeTableColumnRole.Edge).Select(e => e.Key))
{
var elementList = starReplacement.GetOrCreate(alias);
elementList.Add(new WSelectScalarExpression
{
SelectExpr = new WColumnReferenceExpression
{
MultiPartIdentifier = new WMultiPartIdentifier
{
Identifiers = new List<Identifier>
{
new Identifier {Value = alias},
new Identifier {Value = column}
}
}
}
});
}
if (graph == null) continue;
foreach (var subGraph in graph.ConnectedSubGraphs)
{
if (subGraph.Nodes.ContainsKey(alias))
{
var matchNode = subGraph.Nodes[alias];
foreach (var edge in matchNode.Neighbors)
{
var schemaName = edge.SourceNode.NodeTableObjectName.SchemaIdentifier ==
null
? "dbo"
: edge.SourceNode.NodeTableObjectName.SchemaIdentifier.Value.ToLower();
var nodeTuple = new Tuple<string, string>(schemaName,
edge.SourceNode.NodeTableObjectName.BaseIdentifier.Value.ToLower());
var edgeColumnName =
edge.EdgeColumn.MultiPartIdentifier.Identifiers.Last().Value.ToLower();
if (!_graphMetaData.ColumnsOfNodeTables[nodeTuple].ContainsKey(edgeColumnName))
{
throw new GraphViewException("Invalid Edge Alias");
}
foreach (
var column in
_graphMetaData.ColumnsOfNodeTables[nodeTuple][edgeColumnName].EdgeInfo
.ColumnAttributes)
{
var elementList = starReplacement.GetOrCreate(edge.EdgeAlias);
elementList.Add(new WSelectScalarExpression
{
SelectExpr = new WColumnReferenceExpression
{
MultiPartIdentifier = new WMultiPartIdentifier
{
Identifiers = new List<Identifier>
{
new Identifier {Value = edge.EdgeAlias},
new Identifier {Value = column}
}
}
}
});
}
}
}
}
}
else
{
var derivedTable = table.Value as WQueryDerivedTable;
if (derivedTable == null)
continue;
var elementList = starReplacement.GetOrCreate(alias);
elementList.Add(new WSelectStarExpression
{
Qulifier = new WMultiPartIdentifier
{
Identifiers = new List<Identifier> {new Identifier {Value = alias}}
}
});
}
}
}
if (starElement.Qulifier != null)
{
newSelectElements.AddRange(starReplacement[starElement.Qulifier.Identifiers.Last().Value]);
}
else
{
foreach (var value in starReplacement.Values)
{
newSelectElements.AddRange(value);
}
}
}
else
{
newSelectElements.Add(element);
}
}
if (newSelectElements.Any())
node.SelectElements = newSelectElements;
}
/// <summary>
/// Construct Graph from the match clause. The Graph can consist of multiple connected SubGraph.
/// Not supported in this version
/// </summary>
/// <param name="query"></param>
/// <returns></returns>
private MatchGraph ConstructGraph(WSelectQueryBlock query)
{
var unionFind = new UnionFind();
if (query.MatchClause == null)
return null;
var edgeTableReferenceDict = new Dictionary<string, List<string>>(StringComparer.CurrentCultureIgnoreCase);
var matchClause = query.MatchClause;
var nodes = new Dictionary<string, MatchNode>(StringComparer.CurrentCultureIgnoreCase);
var connectedSubGraphs = new List<ConnectedComponent>();
var subGrpahMap = new Dictionary<string, ConnectedComponent>(StringComparer.CurrentCultureIgnoreCase);
var parent = new Dictionary<string, string>(StringComparer.CurrentCultureIgnoreCase);
unionFind.Parent = parent;
HashSet<Tuple<string, string>> nodeTypes = new HashSet<Tuple<string, string>>();
//Construct Graph from Match Pattern
foreach (var path in matchClause.Paths)
{
var index = 0;
MatchEdge preEdge = null;
for (var count = path.PathNodeList.Count; index < count; ++index)
{
var currentNode = path.PathNodeList[index].Item1;
var currentEdge = path.PathNodeList[index].Item2;
var currentNodeExposedName = currentNode.BaseIdentifier.Value;
var nextNode = index != count - 1
? path.PathNodeList[index + 1].Item1
: path.Tail;
var nextNodeExposedName = nextNode.BaseIdentifier.Value;
var node = nodes.GetOrCreate(currentNodeExposedName);
if (node.NodeAlias == null)
{
node.NodeAlias = currentNodeExposedName;
node.Neighbors = new List<MatchEdge>();
node.External = false;
var nodeTable = _context[currentNodeExposedName] as WNamedTableReference;
if (nodeTable != null)
{
node.TableObjectName = nodeTable.TableObjectName;
if (node.TableObjectName.SchemaIdentifier == null)
node.TableObjectName.Identifiers.Insert(0, new Identifier { Value = "dbo" });
var nodeTypeTuple = WNamedTableReference.SchemaNameToTuple(node.TableObjectName);
if (!nodeTypes.Contains(nodeTypeTuple))
nodeTypes.Add(nodeTypeTuple);
}
}
if (currentEdge.AliasRole == AliasType.Default)
{
var currentEdgeName = currentEdge.MultiPartIdentifier.Identifiers.Last().Value;
if (edgeTableReferenceDict.ContainsKey(currentEdgeName))
{
edgeTableReferenceDict[currentEdgeName].Add(currentEdge.Alias);
}
else
{
edgeTableReferenceDict.Add(currentEdgeName, new List<string> { currentEdge.Alias });
}
}
var edge = new MatchEdge
{
SourceNode = node,
EdgeColumn = new WColumnReferenceExpression
{
MultiPartIdentifier = new WMultiPartIdentifier
{
Identifiers = new List<Identifier>
{
new Identifier {Value = node.NodeAlias},
currentEdge.MultiPartIdentifier.Identifiers.Last()
}
}
},
EdgeAlias = currentEdge.Alias
};
if (preEdge != null)
{
preEdge.SinkNode = node;
}
preEdge = edge;
if (!parent.ContainsKey(currentNodeExposedName))
parent[currentNodeExposedName] = currentNodeExposedName;
if (!parent.ContainsKey(nextNodeExposedName))
parent[nextNodeExposedName] = nextNodeExposedName;
unionFind.Union(currentNodeExposedName, nextNodeExposedName);
node.Neighbors.Add(edge);
_context.AddEdgeReference(currentEdge.Alias, edge.SourceNode.TableObjectName, currentEdge);
}
var tailExposedName = path.Tail.BaseIdentifier.Value;
var tailNode = nodes.GetOrCreate(tailExposedName);
if (tailNode.NodeAlias == null)
{
tailNode.NodeAlias = tailExposedName;
tailNode.Neighbors = new List<MatchEdge>();
var nodeTable = _context[tailExposedName] as WNamedTableReference;
if (nodeTable != null)
{
tailNode.TableObjectName = nodeTable.TableObjectName;
if (tailNode.TableObjectName.SchemaIdentifier == null)
tailNode.TableObjectName.Identifiers.Insert(0, new Identifier { Value = "dbo" });
var nodeTypeTuple = WNamedTableReference.SchemaNameToTuple(tailNode.TableObjectName);
if (!nodeTypes.Contains(nodeTypeTuple))
nodeTypes.Add(nodeTypeTuple);
}
}
if (preEdge != null)
preEdge.SinkNode = tailNode;
}
// Put nodes into subgraphs
foreach (var node in nodes)
{
string root = unionFind.Find(node.Key);
if (!subGrpahMap.ContainsKey(root))
{
var subGraph = new ConnectedComponent();
subGraph.Nodes[node.Key] = node.Value;
foreach (var edge in node.Value.Neighbors)
{
subGraph.Edges[edge.EdgeAlias] = edge;
}
subGrpahMap[root] = subGraph;
connectedSubGraphs.Add(subGraph);
subGraph.IsTailNode[node.Value] = false;
}
else
{
var subGraph = subGrpahMap[root];
subGraph.Nodes[node.Key] = node.Value;
foreach (var edge in node.Value.Neighbors)
{
subGraph.Edges[edge.EdgeAlias] = edge;
}
subGraph.IsTailNode[node.Value] = false;
}
}
// Replace Edge name alias with proper alias in the query
var replaceTableRefVisitor = new ReplaceTableRefVisitor();
replaceTableRefVisitor.Invoke(query, edgeTableReferenceDict);
// If a table alias in the MATCH clause is defined in an upper-level context,
// to be able to translate this MATCH clause, this table alias must be re-materialized
// in the FROM clause of the current context and joined with the corresponding table
// in the upper-level context.
var tableRefs = query.FromClause.TableReferences;
var tableSet = new HashSet<string>(StringComparer.CurrentCultureIgnoreCase);
var newTableRefs = new List<WTableReference>();
for (int index = 0; index < tableRefs.Count; ++index)
{
var table = tableRefs[index] as WNamedTableReference;
if (table == null)
{
newTableRefs.Add(tableRefs[index]);
continue;
}
var tableTuple = WNamedTableReference.SchemaNameToTuple(table.TableObjectName);
if (!nodeTypes.Contains(tableTuple))
{
newTableRefs.Add(table);
}
else
{
tableSet.Add(table.ExposedName.Value);
}
}
query.FromClause = new WFromClause
{
TableReferences = newTableRefs,
};
WBooleanExpression whereCondiction = null;
foreach (var node in nodes)
{
if (!tableSet.Contains(node.Key))
{
node.Value.External = true;
var newWhereCondition = new WBooleanComparisonExpression
{
ComparisonType = BooleanComparisonType.Equals,
FirstExpr = new WColumnReferenceExpression
{
MultiPartIdentifier = new WMultiPartIdentifier(
new Identifier { Value = node.Key },
new Identifier { Value = "GlobalNodeId" })
},
SecondExpr = new WColumnReferenceExpression
{
MultiPartIdentifier = new WMultiPartIdentifier(
new Identifier { Value = node.Value.RefAlias },
new Identifier { Value = "GlobalNodeId" })
},
};
whereCondiction = WBooleanBinaryExpression.Conjunction(whereCondiction, newWhereCondition);
}
}
if (whereCondiction != null)
{
if (query.WhereClause == null)
{
query.WhereClause = new WWhereClause { SearchCondition = whereCondiction };
}
else
{
if (query.WhereClause.SearchCondition == null)
{
query.WhereClause.SearchCondition = whereCondiction;
}
else
{
query.WhereClause.SearchCondition = new WBooleanBinaryExpression
{
BooleanExpressionType = BooleanBinaryExpressionType.And,
FirstExpr = new WBooleanParenthesisExpression
{
Expression = query.WhereClause.SearchCondition
},
SecondExpr = new WBooleanParenthesisExpression
{
Expression = whereCondiction
}
};
}
}
}
var graph = new MatchGraph
{
ConnectedSubGraphs = connectedSubGraphs,
NodeTypesSet = nodeTypes,
};
unionFind.Parent = null;
return graph;
}
/// <summary>
/// Checks the validity of the MATCH clause, including
/// (1) an edge is bound to a node table or node view,
/// (2) the source and the sink of an edeg in a path expression are bound to corresponding node tables,
/// as specified when node tables are created, and
/// (3) The length constraint for a path construct is valid
/// </summary>
/// <param name="node">True, if the MATCH clause passes the test; false, otherwise.</param>
private void CheckValidity(WSelectQueryBlock node)
{
if (node.MatchClause == null)
return;
// Checks validity of the source node/node view
if (node.MatchClause.Paths.All(
path => path.PathEdgeList.All(
part => _context.CheckTable(part.Item1.BaseIdentifier.Value) &&
IsNodeTable(_context[part.Item1.BaseIdentifier.Value])
)
))
{
foreach (var path in node.MatchClause.Paths)
{
var index = 0;
for (var count = path.PathEdgeList.Count; index < count; ++index)
{
var pathNode = path.PathEdgeList[index];
var table = _context[pathNode.Item1.BaseIdentifier.Value] as WNamedTableReference;
var edgeCol = pathNode.Item2;
var edge =
edgeCol.MultiPartIdentifier.Identifiers.Last().Value.ToLower();
var nodeTableTuple = WNamedTableReference.SchemaNameToTuple(table.TableObjectName);
var schema = nodeTableTuple.Item1;
// Binds edge/edge view to node/node view and check validity
string bindNode = _context.BindEdgeToNode(schema, edge, nodeTableTuple.Item2, _graphMetaData);
if (string.IsNullOrEmpty(bindNode))
throw new GraphViewException(string.Format("Edge/EdgeView {0} cannot be bind to {1}.{2}",
edge,
nodeTableTuple.Item1, nodeTableTuple.Item2));
// Check edge length
if (edgeCol.MinLength<0)
throw new GraphViewException(
string.Format(
"The minimal length of the path {0} should be non-negative integer",
edge));
if (edgeCol.MaxLength!=-1 && edgeCol.MinLength > edgeCol.MaxLength)
throw new GraphViewException(
string.Format(
"The minimal length of the path {0} should not be larger than the maximal length",
edge));
// Checks whether the sink of the edge/edge view exist
HashSet<string> edgeSinkNodes =
_graphMetaData.ColumnsOfNodeTables[new Tuple<string, string>(schema, bindNode)][edge].EdgeInfo
.SinkNodes;
HashSet<string> sinkNodes;
if (
!edgeSinkNodes.All(
e =>
_graphMetaData.ColumnsOfNodeTables.ContainsKey(new Tuple<string, string>(
schema.ToLower(), e))))
throw new GraphViewException(String.Format(CultureInfo.CurrentCulture,
"Node Table Referenced by the Edge {0} not exists", edge));
// Checks validity of sink node(s)
var nextNode = index != count - 1
? path.PathEdgeList[index + 1].Item1
: path.Tail;
var getNextTable = _context[nextNode.BaseIdentifier.Value];
if (!IsNodeTable(getNextTable))
throw new GraphViewException("Node table expected in MATCH clause");
// Checks whether the intersection of the edge sink and sink node(s) is empty
var nextTable = getNextTable as WNamedTableReference;
if (nextTable == null ||
!_graphMetaData.NodeViewMapping.TryGetValue(
WNamedTableReference.SchemaNameToTuple(nextTable.TableObjectName), out sinkNodes))
sinkNodes = new HashSet<string> {nextTable.TableObjectName.BaseIdentifier.Value};
if (sinkNodes.All(e => !edgeSinkNodes.Contains(e)))
{
throw new GraphViewException(String.Format(CultureInfo.CurrentCulture,
"Wrong Reference Table {0}", nextTable.TableObjectName.BaseIdentifier.Value));
}
}
}
}
else
{
throw new GraphViewException("Node table/view expected in MATCH clause");
}
}
public override void Visit(WSelectQueryBlock node)
{
base.Visit(node);
var flag = false;
for (var i = 0; i < MatchList.Count; ++i)
{
if (MatchFlag[i])
{
continue;
}
var nextToken = node.LastTokenIndex + 1;
while (nextToken < Tokens.Count && Tokens[nextToken].TokenType == TSqlTokenType.WhiteSpace)
{
nextToken++;
}
var insideBlock = (node.FirstTokenIndex < MatchList[i].FirstTokenIndex &&
(node.LastTokenIndex > MatchList[i].LastTokenIndex ||
nextToken == MatchList[i].FirstTokenIndex));
if (!insideBlock)
{
continue;
}
nextToken = node.FromClause.LastTokenIndex + 1;
while (nextToken < Tokens.Count && Tokens[nextToken].TokenType == TSqlTokenType.WhiteSpace)
{
nextToken++;
}
// match clause should exactly follow FROM clause
if (node.FromClause.TableReferences == null ||
nextToken != MatchList[i].FirstTokenIndex)
{
var token = Tokens[nextToken];
_errors.Add(new ParseError(0, token.Offset, token.Line, token.Column,
"MATCH clause should exactly follow FROM clause"));
}
// if a where/top row filter/group by/having clause exists, it should be followed by a match clause
if (node.WhereClause.SearchCondition != null &&
node.WhereClause.FirstTokenIndex < MatchList[i].LastTokenIndex)
{
var token = Tokens[nextToken];
_errors.Add(new ParseError(0, token.Offset, token.Line, token.Column,
"WHERE clause should be followed by a MATCH clause"));
}
if (node.TopRowFilter != null &&
node.TopRowFilter.FirstTokenIndex < MatchList[i].LastTokenIndex)
{
var token = Tokens[nextToken];
_errors.Add(new ParseError(0, token.Offset, token.Line, token.Column,
"Top row filter should be followed by a MATCH clause"));
}
if (node.GroupByClause != null &&
node.GroupByClause.FirstTokenIndex < MatchList[i].LastTokenIndex)
{
var token = Tokens[nextToken];
_errors.Add(new ParseError(0, token.Offset, token.Line, token.Column,
"GROUP BY clause should be followed by a MATCH clause"));
}
if (node.HavingClause != null &&
node.HavingClause.FirstTokenIndex < MatchList[i].LastTokenIndex)
{
var token = Tokens[nextToken];
_errors.Add(new ParseError(0, token.Offset, token.Line, token.Column,
"HAVING clause should be followed by a MATCH clause"));
}
if (flag)
{
var token = Tokens[nextToken];
_errors.Add(new ParseError(0, token.Offset, token.Line, token.Column,
"Mutiple MATCH clauses in same query block"));
}
if (_errors.Count > 0)
{
return;
}
if (node.LastTokenIndex < MatchList[i].FirstTokenIndex)
{
node.LastTokenIndex = MatchList[i].LastTokenIndex;
}
flag = true;
if (node.MatchClause != null && node.MatchClause.Paths != null && node.MatchClause.Paths.Any())
{
foreach (var path in MatchList[i].Paths)
{
node.MatchClause.Paths.Add(path);
}
}
else
{
node.MatchClause = MatchList[i];
}
MatchFlag[i] = true;
}
}