Thread: Problem with coalesce..

----- Original Message -----

From: George Henry C. Daswani

To: pgsql-sql@postgresql.org

Cc: pgsql-general@postgresql.org

Sent: Tuesday, October 31, 2000 5:52 PM

Subject: [SQL] Problem with coalesce..

Hello,

 

    Was wondering if such a call is unsupported, or a bug?

 

7.0.2 (postgresql, linux redhat 7.0)

 

SELECT COALESCE ((SELECT NULL,1)

 

returns a 1, correct..

 

however..

 

SELECT COALESCE ((SELECT CURVALUE FROM TABLEKEYS WHERE TABLENAME = 'BUYER'),1)

 

returns a "UNKNOWN expression type 501"

 

SELECT CURVALUE FROM TABLEKEYS WHERE TABLENAME = 'BUYER'; returns a '0'

 

Thanks..

 

George

 

 

There are still some contexts in which subqueries in expressions are
wierd. The example below appears to work in current sources however.

Stephan Szabo
sszabo@bigpanda.com

On Tue, 31 Oct 2000, George Henry C. Daswani wrote:

> Hello,
>
>     Was wondering if such a call is unsupported, or a bug?
>
> 7.0.2 (postgresql, linux redhat 7.0)
>
> SELECT COALESCE ((SELECT NULL,1)
>
> returns a 1, correct..
>
> however..
>
> SELECT COALESCE ((SELECT CURVALUE FROM TABLEKEYS WHERE TABLENAME = 'BUYER'),1)
>
> returns a "UNKNOWN expression type 501"
>
> SELECT CURVALUE FROM TABLEKEYS WHERE TABLENAME = 'BUYER'; returns a '0'
>
> Thanks..
>
> George
>
>
>

Stephan Szabo <sszabo@megazone23.bigpanda.com> writes:
> There are still some contexts in which subqueries in expressions are
> wierd. The example below appears to work in current sources however.

>> SELECT COALESCE ((SELECT CURVALUE FROM TABLEKEYS WHERE TABLENAME = 'BUYER'),1)
>> returns a "UNKNOWN expression type 501"

AFAICT it works in 7.0.* as well.  Are you sure this was 7.0.2, and
not 6.5.something?

            regards, tom lane