// generate SQL code for order by
DataTableSql AddOrderBy(ExpressionEval[] expr)
{
if (SqlOrderByText != null)
{
return(DataTableSql.CreateFromSubquery(this).AddOrderBy(expr));
}
SqlOrderByText = _gen.OrderBy(expr);
return(this);
}
//--- functions to manipulate queries
// generate SQL code for restrict
DataTableSql AddWhere(ExpressionEval expr, bool hasgroupby)
{
if (SqlWhereText != null)
{
return(DataTableSql.CreateFromSubquery(this).AddWhere(expr, hasgroupby));
}
SqlWhereText = (hasgroupby) ? _gen.Having(expr) : _gen.Where(expr);
return(this);
}