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));
}
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));
}
