protected override Expression VisitSelect(SelectExpression select)
{
select = (SelectExpression)base.VisitSelect(select);
if (_lookup.Contains(select.Alias))
{
var fields = new List<FieldDeclaration>(select.Fields);
foreach (var ae in _lookup[select.Alias])
{
var name = "_$agg" + fields.Count;
var field = new FieldDeclaration(name, ae.AggregateInGroupSelect);
if (_map.ContainsKey(ae))
continue;
_map.Add(ae, new FieldExpression(ae.AggregateInGroupSelect, ae.GroupByAlias, name));
fields.Add(field);
}
return new SelectExpression(select.Alias, fields, select.From, select.Where, select.OrderBy, select.GroupBy, select.IsDistinct, select.Skip, select.Take);
}
return select;
}
protected virtual bool CompareFieldDeclaration(FieldDeclaration a, FieldDeclaration b)
{
return(a.Name == b.Name && Compare(a.Expression, b.Expression));
}
public static SelectExpression AddField(this SelectExpression select, FieldDeclaration field)
{
var fields = new List<FieldDeclaration>(select.Fields) {field};
return select.SetFields(fields);
}
public static SelectExpression RemoveField(this SelectExpression select, FieldDeclaration field)
{
var fields = new List<FieldDeclaration>(select.Fields);
fields.Remove(field);
return select.SetFields(fields);
}
protected virtual bool CompareFieldDeclaration(FieldDeclaration a, FieldDeclaration b)
{
return a.Name == b.Name && Compare(a.Expression, b.Expression);
}