----- Original Message -----
From: <karol(at)gmweltel(dot)com(dot)pl>
> INSERT INTO table1 VALUES SELECT DISTINCT null,table2.atr1 FROM table2
> WHERE table2.atr1 > 0;
>
> It works in PostgreSQL 6.4.2 but in 7.0.3 it returns:
>
> ERROR: Unable to identify an ordering operator '<' for type 'unknown'
> Use an explicit ordering operator or modify the query
>
> I discovered that PostgreSQL 7.0.3 doesn't accept the querry:
>
> select distinct null;
>
Casting the null seems to do it.
select distinct null::text,a from foo;
works OK on my 7.0 here
- Richard Huxton