protected virtual Expression VisitSubquery(SubqueryExpression subquery)
{
switch ((DbExpressionType)subquery.NodeType)
{
case DbExpressionType.Scalar:
return this.VisitScalar((ScalarExpression)subquery);
case DbExpressionType.Exists:
return this.VisitExists((ExistsExpression)subquery);
case DbExpressionType.In:
return this.VisitIn((InExpression)subquery);
}
return subquery;
}
protected override Expression VisitSubquery(SubqueryExpression subquery)
{
// don't gather inside scalar & exists
return subquery;
}
protected override Expression VisitSubquery(SubqueryExpression subquery)
{
// don't count aggregates in subqueries
return subquery;
}
protected override Expression VisitSubquery(SubqueryExpression subquery)
{
return subquery;
}
protected virtual bool CompareSubquery(SubqueryExpression a, SubqueryExpression b)
{
if (a.NodeType != b.NodeType)
return false;
switch ((DbExpressionType)a.NodeType)
{
case DbExpressionType.Scalar:
return this.CompareScalar((ScalarExpression)a, (ScalarExpression)b);
case DbExpressionType.Exists:
return this.CompareExists((ExistsExpression)a, (ExistsExpression)b);
case DbExpressionType.In:
return this.CompareIn((InExpression)a, (InExpression)b);
}
return false;
}
protected override Expression VisitSubquery(SubqueryExpression subquery)
{
if ((subquery.NodeType == (ExpressionType)DbExpressionType.Scalar ||
subquery.NodeType == (ExpressionType)DbExpressionType.In) &&
subquery.Select != null)
{
System.Diagnostics.Debug.Assert(subquery.Select.Fields.Count == 1);
MarkFieldAsUsed(subquery.Select.Alias, subquery.Select.Fields[0].Name);
}
return base.VisitSubquery(subquery);
}
