private WSelectElement ParseSelectElement(SelectElement sel)
{
if (sel == null)
{
return null;
}
switch (sel.GetType().Name)
{
case "SelectScalarExpression":
{
var sse = sel as SelectScalarExpression;
var pScalarExpr = new WSelectScalarExpression
{
SelectExpr = ParseScalarExpression(sse.Expression),
FirstTokenIndex = sse.FirstTokenIndex,
LastTokenIndex = sse.LastTokenIndex
};
if (sse.ColumnName != null)
{
pScalarExpr.ColumnName = sse.ColumnName.Value;
}
return pScalarExpr;
}
case "SelectStarExpression":
{
var sse = sel as SelectStarExpression;
return new WSelectStarExpression()
{
FirstTokenIndex = sse.FirstTokenIndex,
LastTokenIndex = sse.LastTokenIndex,
Qulifier = ParseMultiPartIdentifier(sse.Qualifier)
};
}
case "SelectSetVariable":
{
var ssv = sel as SelectSetVariable;
return new WSelectSetVariable
{
VariableName = ssv.Variable.Name,
Expression = ParseScalarExpression(ssv.Expression),
AssignmentType = ssv.AssignmentKind,
FirstTokenIndex = ssv.FirstTokenIndex,
LastTokenIndex = ssv.LastTokenIndex
};
}
default:
{
return null;
}
}
}
public virtual void Visit(WSelectScalarExpression node)
{
node.AcceptChildren(this);
}
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;
}
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,
}
};
}
public virtual void Visit(WSelectScalarExpression node)
{
node.AcceptChildren(this);
}
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,
}
},
}
};
}