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* time of constraint checking
@ 2004-10-20 15:58 Markus Bertheau <twanger@bluetwanger.de>
0 siblings, 2 replies; 3+ messages in thread
From: Markus Bertheau @ 2004-10-20 15:58 UTC (permalink / raw)
To: pgsql-sql
Hi,
http://www.postgresql.org/docs/current/static/sql-createtable.html says,
down at the explanation of DEFERRABLE, that constraints are checked
after every command. Why does the following not work then:
CREATE TABLE foo (
pos INT UNIQUE
);
INSERT INTO foo (pos) VALUES (1);
INSERT INTO foo (pos) VALUES (2);
UPDATE foo SET pos = CASE WHEN pos = 2 THEN 1 ELSE 2 END;
ERROR: duplicate key violates unique constraint "foo_pos_key"
Also, are deferrable constraints other that FK constraints in the works?
I also noticed, that the docs don't state whether INITIALLY IMMEDIATE or
INITIALLY DEFERRED is the default.
Thanks.
--
Markus Bertheau <twanger@bluetwanger.de>
^ permalink raw reply [nested|flat] 3+ messages in thread
* Re: time of constraint checking
@ 2004-10-20 16:16 Markus Bertheau <twanger@bluetwanger.de>
parent: Markus Bertheau <twanger@bluetwanger.de>
1 sibling, 0 replies; 3+ messages in thread
From: Markus Bertheau @ 2004-10-20 16:16 UTC (permalink / raw)
To: pgsql-sql
В Срд, 20.10.2004, в 17:58, Markus Bertheau пишет:
> I also noticed, that the docs don't state whether INITIALLY IMMEDIATE or
> INITIALLY DEFERRED is the default.
I just overlooked that, sorry, it is stated.
--
Markus Bertheau <twanger@bluetwanger.de>
^ permalink raw reply [nested|flat] 3+ messages in thread
* Re: time of constraint checking
@ 2004-10-20 16:56 Stephan Szabo <sszabo@megazone.bigpanda.com>
parent: Markus Bertheau <twanger@bluetwanger.de>
1 sibling, 0 replies; 3+ messages in thread
From: Stephan Szabo @ 2004-10-20 16:56 UTC (permalink / raw)
To: Markus Bertheau <twanger@bluetwanger.de>; +Cc: pgsql-sql
On Wed, 20 Oct 2004, Markus Bertheau wrote:
> http://www.postgresql.org/docs/current/static/sql-createtable.html says,
> down at the explanation of DEFERRABLE, that constraints are checked
> after every command. Why does the following not work then:
>
> CREATE TABLE foo (
> pos INT UNIQUE
> );
>
> INSERT INTO foo (pos) VALUES (1);
> INSERT INTO foo (pos) VALUES (2);
>
> UPDATE foo SET pos = CASE WHEN pos = 2 THEN 1 ELSE 2 END;
> ERROR: duplicate key violates unique constraint "foo_pos_key"
Unique constraints are currently non-compliant in that it checks on each
changed row rather than at the end of the statement. I thought this was
mentioned somewhere, but it might make sense to mention it in the
compatibility section.
> Also, are deferrable constraints other that FK constraints in the works?
I don't think anyone's looking at it right now.
^ permalink raw reply [nested|flat] 3+ messages in thread
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2004-10-20 15:58 time of constraint checking Markus Bertheau <twanger@bluetwanger.de>
2004-10-20 16:16 ` Markus Bertheau <twanger@bluetwanger.de>
2004-10-20 16:56 ` Stephan Szabo <sszabo@megazone.bigpanda.com>
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