Re: Temporal foreign keys

Jeff Davis <pgsql@j-davis.com> wrote:

> On Fri, 2012-02-03 at 07:58 +0100, Matthias wrote:
> > Hey,
> >
> > how can I implement temporal foreign keys with postgresql? Is writing
> > triggers the only way to enforce temporal referential integrity
> > currently?
>
> Yes, currently that's the only way. Look at CREATE CONSTRAINT TRIGGER.

It works in 9.2devel ;-)

test=# create table x (d daterange primary key);
NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "x_pkey"
for table "x"
CREATE TABLE
test=*# create table y (d daterange references x);
CREATE TABLE
test=*# insert into x values ('[2012-01-01,2012-01-10)');
INSERT 0 1
test=*# insert into y values ('[2012-01-01,2012-01-10)');
INSERT 0 1
test=*# insert into y values ('[2012-01-01,2012-01-20)');
ERROR:  insert or update on table "y" violates foreign key constraint "y_d_fkey"
DETAIL:  Key (d)=([2012-01-01,2012-01-20)) is not present in table "x".



Jeff: thx for YOUR work!


Andreas
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