Thread: sorry, now with subject... trigger & nextval(seq)

Hello all,

I'm new to triggers in PostgreSQL. I have to create a trigger on insert to
increment a sequence to overcome MS-Access' limitation in acknowledging
serial "datatype".

Could anyone put me on right track? I was looking the whole day for
references on that... Years ago I quickly found a reference how to do it
in Oracle. However, I could not find anything that explained how to do
this in postgresql... I think, it should go the direction see below... But
how exactly :-/ ?


Many thanks for any help, Torsten


create table testtab ( pid bigint, sometext text
);

create sequence test;

-- hmm something like this...?
CREATE FUNCTION count_up (varchar) RETURNS opaque AS ' DECLARE   pid_num bigint; BEGIN   select into pid_num from
selectnextval($);   RETURN pid_num; END;
 
' LANGUAGE 'plpgsql';

-- and how will the trigger looks like
???

On Thursday 20 May 2010 5:53:51 pm tlange@gwdg.de wrote:
> Hello all,
>
> I'm new to triggers in PostgreSQL. I have to create a trigger on insert to
> increment a sequence to overcome MS-Access' limitation in acknowledging
> serial "datatype".
>
> Could anyone put me on right track? I was looking the whole day for
> references on that... Years ago I quickly found a reference how to do it
> in Oracle. However, I could not find anything that explained how to do
> this in postgresql... I think, it should go the direction see below... But
> how exactly :-/ ?
>
>
> Many thanks for any help, Torsten
>
>
> create table testtab (
>   pid bigint,
>   sometext text
> );
>
> create sequence test;
>
> -- hmm something like this...?
> CREATE FUNCTION count_up (varchar) RETURNS opaque AS '
>   DECLARE
>     pid_num bigint;
>   BEGIN
>     select into pid_num from select nextval($);
>     RETURN pid_num;
>   END;
> ' LANGUAGE 'plpgsql';
>
> -- and how will the trigger looks like
> ???

You know serial is just a shortcut for:

pid int NOT NULL DEFAULT nextval('seq')

I think you will find Access will place nice if you use the long form to define 
your autoincrement.



-- 
Adrian Klaver
adrian.klaver@gmail.com

Am 21.05.2010 03:46, schrieb Adrian Klaver:
> You know serial is just a shortcut for:
>
> pid int NOT NULL DEFAULT nextval('seq')
>
> I think you will find Access will place nice if you use the long form to define
> your autoincrement.
>
Not true. Serial will also add an internal dependency between the
sequence, will create the sequence and will drop everything if the
column gets dropped.

Regards,
Daniel Migowski