protected override Expression VisitSubquery(SubqueryExpression subquery)
{
if ((subquery.NodeType == (ExpressionType)DbExpressionType.Scalar ||
subquery.NodeType == (ExpressionType)DbExpressionType.In) &&
subquery.Select != null)
{
if (subquery.Select.Columns.Count != 1)
throw new InvalidOperationException("Subquery has {0} columns: {1}".Formato(subquery.Select.Columns.Count, subquery.NiceToString()));
allColumnsUsed.GetOrCreate(subquery.Select.Alias).Add(subquery.Select.Columns[0].Name);
}
return base.VisitSubquery(subquery);
}
