Thread: Re: postgresql experts please help

Re: postgresql experts please help

From
Michael Schmidt
Date:
There is:

SELECT currval(pg_get_serial_sequence('mytab','mycol'));


Tried this as an isolated statement and it returned null, so it appears
to also require that nextval be run before it can work.

Michael Schmidt

Re: postgresql experts please help

From
Kris Jurka
Date:

On Thu, 18 Oct 2007, Michael Schmidt wrote:

> There is:
>
> SELECT currval(pg_get_serial_sequence('mytab','mycol'));
>
>
> Tried this as an isolated statement and it returned null, so it appears to
> also require that nextval be run before it can work.
>

No one was ever saying otherwise.  All this discussion is focused around
the example that Andrei provided where an insert was done on a table with
a serial column.

In your case you're getting NULL because pg_get_serial_sequence returns
NULL for a column that doesn't have a sequence attached to it and currval
is STRICT.  If you try this on something that is actually a serial column
you will get the expected error instead of NULL.

Kris Jurka