public override ExpressionNode VisitAggregagateExpression(AggregateExpression expression)
{
MetaInfo metaInfo = AstUtil.GetMetaInfo(expression.Argument);
// Find associated query scope and ensure the aggregate's argument does not mix
// tables from different query scopes.
QueryScope associatedScope = null;
foreach (TableRefBinding tableDependency in metaInfo.TableDependencies)
{
if (associatedScope == null)
{
associatedScope = tableDependency.Scope;
}
else if (associatedScope != tableDependency.Scope)
{
_errorReporter.AggregateContainsColumnsFromDifferentQueries(expression.Argument);
}
}
// Enter aggregate dependency.
AddAggregateDependency(associatedScope, expression);
return(expression);
}
private ICollection <AggregateExpression> GetAggregateDependencies(QueryScope associatedScope)
{
AggregateList associatedAggregateExpressions;
if (_aggregateDependencies.TryGetValue(associatedScope, out associatedAggregateExpressions))
{
return(associatedAggregateExpressions.Values);
}
return(null);
}
private bool QueryHasAggregates(QueryScope queryScope)
{
if (_unscopedAggregateExpressionStack.Peek().Values.Count > 0)
{
return(true);
}
AggregateList queryAggregateList;
if (_aggregateDependencies.TryGetValue(queryScope, out queryAggregateList) &&
queryAggregateList.Values.Count > 0)
{
return(true);
}
return(false);
}
private void AddAggregateDependency(QueryScope associatedScope, AggregateExpression aggregateExpression)
{
if (associatedScope == null)
{
AggregateList currentUnscopedAggregateList = _unscopedAggregateExpressionStack.Peek();
currentUnscopedAggregateList.Add(aggregateExpression);
}
else
{
AggregateList associatedAggregateExpressions;
if (!_aggregateDependencies.TryGetValue(associatedScope, out associatedAggregateExpressions))
{
associatedAggregateExpressions = new AggregateList();
_aggregateDependencies.Add(associatedScope, associatedAggregateExpressions);
}
associatedAggregateExpressions.Add(aggregateExpression);
}
}
public QueryScope(QueryScope parentScope)
{
_parentScope = parentScope;
}
public void PushQueryScope(QueryScope queryScope)
{
_queryScopeStack.Push(queryScope);
}
private bool IsOuterScope(QueryScope scope)
{
return(!_queryScopeStack.Contains(scope));
}