select distinct null
Hello!
I've got problem with such a query:
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;
and reurns the same error.
I use such queries in some client applications and it would be hard
to rewrite them. Could anyone explain to me what has been changed in 7.0.3
and how can I solve the problem on the server side.
Thanks in advance.
Karol Wieloch
----- Original Message -----
From: <karol@gmweltel.com.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 queryI 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
On Thu, 4 Jan 2001, Richard Huxton wrote:
Casting the null seems to do it.
select distinct null::text,a from foo;
works OK on my 7.0 here
Thanks! It works on my too so I will have hardly any trouble to fix the
queries.
But I'm just wondering if there is some solution not involving
any modification of the query code.
Karol Wieloch
<karol@gmweltel.com.pl> writes:
On Thu, 4 Jan 2001, Richard Huxton wrote:
Casting the null seems to do it.
select distinct null::text,a from foo;
works OK on my 7.0 here
Thanks! It works on my too so I will have hardly any trouble to fix the
queries.
But I'm just wondering if there is some solution not involving
any modification of the query code.
Update to 7.1 ...
regards, tom lane