Re: Returning empty on insert

On 5/16/19 7:10 AM, Winanjaya Amijoyo wrote:
> Hi David,
>
> thanks for your advise, as I am new with postgresql..
> I try to use LOCK as below, but it does not returning pid?
> what I missed?

I'm not sure which pid you are referring to, the INSERT or UPDATE or both?

Can you show the output of the query?
>
> BEGIN TRANSACTION;
> LOCK TABLE test IN ACCESS EXCLUSIVE MODE;
> WITH s AS (
>    SELECT pid FROM test WHERE area = 'test4'
> ), i AS (
>    INSERT INTO test (area)
>    SELECT 'test4'
>    WHERE NOT EXISTS (SELECT 1 FROM s)
>    RETURNING pid
> )
> UPDATE area
> SET last_update = CURRENT_TIMESTAMP
> WHERE pid = (SELECT pid FROM s UNION SELECT pid FROM i)
> RETURNING pid;
> COMMIT TRANSACTION;
>
>

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com