/// <summary>
/// Constructs parameters for the edge table-valued function when translation the MATCH clause
/// </summary>
/// <param name="nodeAlias">Source node alias</param>
/// <param name="nodeTableNameSet">Node table names mapping to the source node of the edge.
/// If null, the source node is mapped to a physical table in the syntax tree. Otherewise,
/// the source node is mapped to a node view</param>
/// <param name="edgeNameTuples">A tuple (Node table name, Edge column name) mapping to the edge.
/// If null, the edge is mapped to an edge column in a physical node table. Ohterwise,
/// the edge is mapped to an edge view</param>
/// <returns>Parameters in the table-valued function</returns>
protected List <WScalarExpression> ConstructEdgeTvfParameters(string nodeAlias,
HashSet <string> nodeTableNameSet = null, List <Tuple <string, string> > edgeNameTuples = null)
{
var edgeIdentifiers = EdgeColumn.MultiPartIdentifier.Identifiers;
var edgeColIdentifier = edgeIdentifiers.Last();
Identifier srcNodeIdentifier = new Identifier {
Value = nodeAlias
};
List <WScalarExpression> parameters = new List <WScalarExpression>();
// The source is a physical node
if (nodeTableNameSet == null)
{
// The edge is a physical edge
if (edgeNameTuples == null)
{
parameters.Add(new WColumnReferenceExpression
{
MultiPartIdentifier =
new WMultiPartIdentifier(srcNodeIdentifier, edgeColIdentifier)
});
parameters.Add(new WColumnReferenceExpression
{
MultiPartIdentifier =
new WMultiPartIdentifier(srcNodeIdentifier,
new Identifier {
Value = edgeColIdentifier.Value + "DeleteCol"
})
});
}
// The edge is an edge view
else
{
foreach (var column in edgeNameTuples)
{
Identifier includedEdgeColumnIdentifier = new Identifier {
Value = column.Item2
};
parameters.Add(new WColumnReferenceExpression
{
MultiPartIdentifier =
new WMultiPartIdentifier(srcNodeIdentifier, includedEdgeColumnIdentifier)
});
parameters.Add(new WColumnReferenceExpression
{
MultiPartIdentifier =
new WMultiPartIdentifier(srcNodeIdentifier,
new Identifier {
Value = includedEdgeColumnIdentifier.Value + "DeleteCol"
})
});
}
}
}
// The source is a node view
else
{
// The edge is a physical edge
if (edgeNameTuples == null)
{
string srcTableName = BindNodeTableObjName.BaseIdentifier.Value;
Identifier nodeViewEdgeColIdentifier = new Identifier
{
Value = srcTableName + "_" + edgeColIdentifier.Value
};
parameters.Add(new WColumnReferenceExpression
{
MultiPartIdentifier =
new WMultiPartIdentifier(srcNodeIdentifier, nodeViewEdgeColIdentifier)
});
parameters.Add(new WColumnReferenceExpression
{
MultiPartIdentifier =
new WMultiPartIdentifier(srcNodeIdentifier,
new Identifier {
Value = nodeViewEdgeColIdentifier.Value + "DeleteCol"
})
});
}
// The edge is an edge view
else
{
foreach (var column in edgeNameTuples)
{
if (nodeTableNameSet.Contains(column.Item1))
{
Identifier includedEdgeColumnIdentifier = new Identifier
{
Value = column.Item1 + "_" + column.Item2
};
parameters.Add(new WColumnReferenceExpression
{
MultiPartIdentifier =
new WMultiPartIdentifier(srcNodeIdentifier, includedEdgeColumnIdentifier)
});
parameters.Add(new WColumnReferenceExpression
{
MultiPartIdentifier =
new WMultiPartIdentifier(srcNodeIdentifier,
new Identifier {
Value = includedEdgeColumnIdentifier.Value + "DeleteCol"
})
});
}
else
{
parameters.Add(new WValueExpression {
Value = "null"
});
parameters.Add(new WValueExpression {
Value = "null"
});
}
}
}
}
return(parameters);
}
/// <summary>
/// Converts the edge to the table-valued function
/// </summary>
/// <param name="nodeAlias">Source node alias</param>
/// <param name="metaData">Meta data</param>
/// <returns>A syntax tree node representing the table-valued function</returns>
public override WSchemaObjectFunctionTableReference ToSchemaObjectFunction(string nodeAlias, GraphMetaData metaData)
{
var edgeIdentifiers = EdgeColumn.MultiPartIdentifier.Identifiers;
var edgeColIdentifier = edgeIdentifiers.Last();
HashSet <string> nodeSet;
if (!metaData.NodeViewMapping.TryGetValue(
WNamedTableReference.SchemaNameToTuple(SourceNode.NodeTableObjectName), out nodeSet))
{
nodeSet = null;
}
var sourceNodeColumns =
metaData.ColumnsOfNodeTables[WNamedTableReference.SchemaNameToTuple(BindNodeTableObjName)];
var edgeInfo = sourceNodeColumns[edgeColIdentifier.Value].EdgeInfo;
List <Tuple <string, string> > edgeTuples = edgeInfo.EdgeColumns;
var parameters = ConstructEdgeTvfParameters(nodeAlias, nodeSet, edgeTuples);
Identifier decoderFunction;
if (ReferencePathInfo)
{
decoderFunction = new Identifier
{
Value = BindNodeTableObjName.SchemaIdentifier.Value + '_' +
BindNodeTableObjName.BaseIdentifier.Value + '_' +
EdgeColumn.MultiPartIdentifier.Identifiers.Last().Value + '_' +
"bfsPathWithMessage"
};
// Node view
if (nodeSet != null)
{
parameters.Insert(0, new WColumnReferenceExpression
{
MultiPartIdentifier =
new WMultiPartIdentifier(new Identifier()
{
Value = SourceNode.RefAlias
},
new Identifier()
{
Value = "_NodeId"
})
});
parameters.Insert(0, new WColumnReferenceExpression
{
MultiPartIdentifier =
new WMultiPartIdentifier(new Identifier()
{
Value = SourceNode.RefAlias
},
new Identifier()
{
Value = "_NodeType"
})
});
}
else
{
string nodeIdName =
sourceNodeColumns.FirstOrDefault(e => e.Value.Role == WNodeTableColumnRole.NodeId).Key;
if (string.IsNullOrEmpty(nodeIdName))
{
parameters.Insert(0, new WValueExpression {
Value = "null"
});
}
else
{
parameters.Insert(0, new WColumnReferenceExpression
{
MultiPartIdentifier =
new WMultiPartIdentifier(new Identifier()
{
Value = SourceNode.RefAlias
},
new Identifier()
{
Value = nodeIdName
})
});
}
parameters.Insert(0,
new WValueExpression {
Value = BindNodeTableObjName.BaseIdentifier.Value, SingleQuoted = true
});
}
}
else
{
decoderFunction = new Identifier
{
Value = BindNodeTableObjName.SchemaIdentifier.Value + '_' +
BindNodeTableObjName.BaseIdentifier.Value + '_' +
EdgeColumn.MultiPartIdentifier.Identifiers.Last().Value + '_' +
"bfsPath"
};
}
parameters.Insert(0, new WValueExpression {
Value = MaxLength.ToString()
});
parameters.Insert(0, new WValueExpression {
Value = MinLength.ToString()
});
parameters.Insert(0,
new WColumnReferenceExpression
{
MultiPartIdentifier =
new WMultiPartIdentifier(new[] { new Identifier {
Value = nodeAlias
}, new Identifier {
Value = "GlobalNodeId"
}, })
});
var attributes = edgeInfo.ColumnAttributes;
if (AttributeValueDict == null)
{
WValueExpression nullExpression = new WValueExpression {
Value = "null"
};
for (int i = 0; i < attributes.Count; i++)
{
parameters.Add(nullExpression);
}
}
else
{
foreach (var attribute in attributes)
{
string value;
var valueExpression = new WValueExpression
{
Value = AttributeValueDict.TryGetValue(attribute, out value) ? value : "null"
};
parameters.Add(valueExpression);
}
}
return(new WSchemaObjectFunctionTableReference
{
SchemaObject = new WSchemaObjectName(
new Identifier {
Value = "dbo"
},
decoderFunction),
Parameters = parameters,
Alias = new Identifier
{
Value = EdgeAlias,
}
});
}
