self-referential UPDATE problem on 7.4
Hello !
I am trying to run this query in psql:
update clin.episode
set fk_patient = clin.health_issue.fk_patient
from clin.health_issue
where
clin.episode.fk_patient is NULL and
clin.episode.fk_health_issue = clin.health_issue.pk;
It returns "UPDATE 2" which is what I expect from the data.
However, the rows in question are not actually updated.
What I am trying to do:
- clin.episode has a nullable foreign key fk_health_issue to clin.health_issue.pk
- clin.health_issue has a not-nullable fk_patient
- clin.episode also has an fk_patient which is nullable
I want to transfer the value of clin.health_issue.fk_patient
to clin.episode.fk_patient to those clin.episodes for which
fk_patient is NULL.
I'm sure I am doing something wrong in a fairly basic way.
I tried with a subselect, too, but get the same result:
update clin.episode
set fk_patient = (
select fk_patient from clin.health_issue chi where chi.pk=clin.episode.fk_health_issue
)
where fk_patient is NULL;
This is on 7.4.14 on Debian/Etch.
Thanks,
Karsten
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GPG key ID E4071346 @ wwwkeys.pgp.net
E167 67FD A291 2BEA 73BD 4537 78B9 A9F9 E407 1346
Karsten Hilbert <Karsten.Hilbert@gmx.net> writes:
I am trying to run this query in psql:
update clin.episode
set fk_patient = clin.health_issue.fk_patient
from clin.health_issue
where
clin.episode.fk_patient is NULL and
clin.episode.fk_health_issue = clin.health_issue.pk;
It returns "UPDATE 2" which is what I expect from the data.
However, the rows in question are not actually updated.
That seems very strange. Could you perhaps have a BEFORE UPDATE trigger
that's changing the values back to null again?
regards, tom lane
On Thu, Jan 04, 2007 at 11:36:35AM -0500, Tom Lane wrote:
update clin.episode
set fk_patient = clin.health_issue.fk_patient
from clin.health_issue
where
clin.episode.fk_patient is NULL and
clin.episode.fk_health_issue = clin.health_issue.pk;It returns "UPDATE 2" which is what I expect from the data.
However, the rows in question are not actually updated.That seems very strange. Could you perhaps have a BEFORE UPDATE trigger
that's changing the values back to null again?
I do but I drop that one in the script before doing the
above update. I may have an old one hanging around, though,
I'll double-check.
Thanks,
Karsten
--
GPG key ID E4071346 @ wwwkeys.pgp.net
E167 67FD A291 2BEA 73BD 4537 78B9 A9F9 E407 1346
On Thu, Jan 04, 2007 at 06:37:23PM +0100, Karsten Hilbert wrote:
It returns "UPDATE 2" which is what I expect from the data.
However, the rows in question are not actually updated.That seems very strange. Could you perhaps have a BEFORE UPDATE trigger
that's changing the values back to null again?I do but I drop that one in the script before doing the
above update. I may have an old one hanging around, though,
I'll double-check.
I was missing a schema qualification in a drop statement,
hence the culprit trigger function wasn't dropped properly.
Sometimes a hint helps.
Thanks Tom,
Karsten
--
GPG key ID E4071346 @ wwwkeys.pgp.net
E167 67FD A291 2BEA 73BD 4537 78B9 A9F9 E407 1346