/// <summary>
/// convert statements in annotation to according graph data modification statements
/// </summary>
/// <param name="script">SQL script</param>
/// <param name="annotations">stores information of data modification statements</param>
/// <returns>Converted script</returns>
private void ConvertToGraphModificationStatement(IList <WSqlStatement> statements)
{
for (var j = 0; j < statements.Count; ++j)
{
var stmt = statements[j];
if (_nodeCount >= _annotations.Count)
{
break;
}
if (stmt is WSelectQueryBlock && stmt.FirstTokenIndex == _annotations[_nodeCount].Position)
{
var newStmt = stmt as WSelectQueryBlock;
var annotation = _annotations[_nodeCount] as DeleteEdgeAnnotation;
if (annotation != null)
{
newStmt.MatchClause = new WMatchClause
{
Paths = new List <WMatchPath>
{
annotation.Path
}
}
}
;
statements[j] = new WDeleteEdgeSpecification(newStmt);
_nodeCount++;
}
if (!(stmt is WInsertSpecification) &&
!(stmt is WDeleteSpecification))
{
continue;
}
if (stmt.LastTokenIndex < _annotations[_nodeCount].Position)
{
continue;
}
if (_annotations[_nodeCount] is InsertNodeAnnotation)
{
statements[j] = new WInsertNodeSpecification(stmt as WInsertSpecification);
}
else if (_annotations[_nodeCount] is InsertEdgeAnnotation)
{
var annotation = _annotations[_nodeCount] as InsertEdgeAnnotation;
statements[j] = new WInsertEdgeSpecification(stmt as WInsertSpecification)
{
EdgeColumn = new WColumnReferenceExpression
{
MultiPartIdentifier = new WMultiPartIdentifier(annotation.EdgeColumn)
},
};
}
else if (_annotations[_nodeCount] is DeleteNodeAnnotation)
{
statements[j] = new WDeleteNodeSpecification(stmt as WDeleteSpecification);
}
_nodeCount++;
}
}
}
public virtual void Visit(WDeleteNodeSpecification node)
{
node.AcceptChildren(this);
}
public virtual void Visit(WDeleteNodeSpecification node)
{
node.AcceptChildren(this);
}
private void TranslateNodeDelete(WDeleteNodeSpecification node, List<WSqlStatement> res)
{
var table = node.Target as WNamedTableReference;
if (table == null)
throw new GraphViewException("Target of DELETE NODE statement should be a named table reference.");
WBooleanExpression cond = new WBooleanComparisonExpression
{
ComparisonType = BooleanComparisonType.Equals,
FirstExpr = new WColumnReferenceExpression
{
MultiPartIdentifier = new WMultiPartIdentifier(new Identifier { Value = "InDegree" })
},
SecondExpr = new WValueExpression
{
Value = "0"
}
};
var tableSchema = table.TableObjectName.SchemaIdentifier == null
? "dbo"
: table.TableObjectName.SchemaIdentifier.Value;
var tableName = table.TableObjectName.BaseIdentifier.Value;
using (var command = Tx.Connection.CreateCommand())
{
command.Transaction = Tx;
command.CommandText = string.Format(
@"SELECT [TableSchema], [TableName], [ColumnName] FROM [{3}] WHERE TableSchema = '{0}' and [TableName]='{1}' and ColumnRole={2}",
tableSchema, tableName, 1, GraphViewConnection.MetadataTables[1]);
using (var reader = command.ExecuteReader())
{
while (reader.Read())
{
var col = reader["ColumnName"].ToString();
cond = WBooleanBinaryExpression.Conjunction(cond, new WBooleanComparisonExpression
{
ComparisonType = BooleanComparisonType.Equals,
FirstExpr = new WColumnReferenceExpression
{
MultiPartIdentifier = new WMultiPartIdentifier(new Identifier { Value = col + "OutDegree" })
},
SecondExpr = new WValueExpression
{
Value = "0"
}
});
}
}
}
WWhereClause checkDeleteNode = new WWhereClause
{
SearchCondition = new WBooleanNotExpression { Expression = new WBooleanParenthesisExpression { Expression = cond } }
};
if (node.WhereClause == null ||
node.WhereClause.SearchCondition == null)
{
node.WhereClause = new WWhereClause { SearchCondition = cond };
}
else
{
checkDeleteNode = new WWhereClause
{
SearchCondition = new WBooleanBinaryExpression
{
BooleanExpressionType = BooleanBinaryExpressionType.And,
FirstExpr = node.WhereClause.SearchCondition,
SecondExpr = checkDeleteNode.SearchCondition
}
};
node.WhereClause = new WWhereClause
{
SearchCondition = new WBooleanBinaryExpression
{
BooleanExpressionType = BooleanBinaryExpressionType.And,
FirstExpr = node.WhereClause.SearchCondition,
SecondExpr = cond
}
};
}
using (var command = Tx.Connection.CreateCommand())
{
command.Transaction = Tx;
command.CommandText = string.Format("SELECT InDegree FROM {0}.{1} {2}", tableSchema, tableName,
checkDeleteNode.ToString());
using (var reader = command.ExecuteReader())
{
while (reader.Read())
{
throw new GraphViewException(
string.Format(
"Node(s) of node table {0} being deleted still has/have ingoing or outdoing edge(s)",
tableName));
}
}
}
res.Add(new WDeleteSpecification
{
FromClause = node.FromClause,
Target = node.Target,
TopRowFilter = node.TopRowFilter,
WhereClause = node.WhereClause,
});
}
/// <summary>
/// convert statements in annotation to according graph data modification statements
/// </summary>
/// <param name="script">SQL script</param>
/// <param name="annotations">stores information of data modification statements</param>
/// <returns>Converted script</returns>
private void ConvertToGraphModificationStatement(IList<WSqlStatement> statements)
{
for (var j = 0; j < statements.Count; ++j)
{
var stmt = statements[j];
if (_nodeCount >= _annotations.Count)
break;
if (stmt is WSelectStatement && stmt.FirstTokenIndex == _annotations[_nodeCount].Position)
{
var newStmt = (stmt as WSelectStatement).QueryExpr as WSelectQueryBlock;
var annotation = _annotations[_nodeCount] as DeleteEdgeAnnotation;
if (annotation != null)
newStmt.MatchClause = new WMatchClause
{
Paths = new List<WMatchPath>
{
annotation.Path
}
};
statements[j] = new WDeleteEdgeSpecification(newStmt);
_nodeCount++;
}
if (!(stmt is WInsertSpecification) &&
!(stmt is WDeleteSpecification))
continue;
if (stmt.LastTokenIndex < _annotations[_nodeCount].Position)
{
continue;
}
if (_annotations[_nodeCount] is InsertNodeAnnotation)
{
statements[j] = new WInsertNodeSpecification(stmt as WInsertSpecification);
}
else if (_annotations[_nodeCount] is InsertEdgeAnnotation)
{
var annotation = _annotations[_nodeCount] as InsertEdgeAnnotation;
statements[j] = new WInsertEdgeSpecification(stmt as WInsertSpecification)
{
EdgeColumn = new WColumnReferenceExpression
{
MultiPartIdentifier = new WMultiPartIdentifier(annotation.EdgeColumn)
},
};
}
else if (_annotations[_nodeCount] is DeleteNodeAnnotation)
{
statements[j] = new WDeleteNodeSpecification(stmt as WDeleteSpecification);
}
_nodeCount++;
}
}