Thread: Dropping all constraints in database

Hello,

Is there a way of disabling/dropping all constrainsts in a given
database? I need to restore a db which has duplicate values in nearly
half of its tables then remove duplicates and then add the constraints
back. Is there a way to do that for each table in one
statement/function? It may be even a java/perl script if it can do
such a thing. Thank You all in advance for help.

--
Łukasz Brodziak
"What if everyting around You isn't quite as it seems,
What if all the world You think You know is an inelaborate dream
When You look at Your reflection is that all you want it to be
What if You could look right through the cracks
Would You find Yourself...... Find Yourself afraid to see"

Lukasz Brodziak, 14.03.2011 10:26:
> Hello,
>
> Is there a way of disabling/dropping all constrainsts in a given
> database? I need to restore a db which has duplicate values in nearly
> half of its tables then remove duplicates and then add the constraints
> back. Is there a way to do that for each table in one
> statement/function? It may be even a java/perl script if it can do
> such a thing. Thank You all in advance for help.
>

Something like this?

DO $body$
DECLARE r record;
BEGIN
    FOR r IN SELECT table_name,constraint_name
             FROM information_schema.constraint_table_usage
    LOOP
       EXECUTE 'ALTER TABLE ' || quote_ident(r.table_name)|| ' DROP CONSTRAINT '|| quote_ident(r.constraint_name) ||
';';
    END LOOP;
END
$body$;


If you are not on 9.x yet, you can simply spool the output of a statement like this:

SELECT 'ALTER TABLE '||table_name||' DROP CONSTRAINT '||constraint_name||';'
FROM information_schema.constraint_table_usage

to a file, and then run that file to drop all constraints.

Regards
Thomas

> From: Lukasz Brodziak <lukasz.brodziak@gmail.com>
> Subject: [ADMIN] Dropping all constraints in database
> To: pgsql-admin@postgresql.org
> Date: Monday, 14 March, 2011, 9:26
> Hello,
>
> Is there a way of disabling/dropping all constrainsts in a
> given
> database? I need to restore a db which has duplicate values
> in nearly
> half of its tables then remove duplicates and then add the
> constraints
> back. Is there a way to do that for each table in one
> statement/function? It may be even a java/perl script if it
> can do
> such a thing. Thank You all in advance for help.
>
>

Magnus Hagander wrote about a method to do that here:

http://blog.hagander.net/archives/131-Automatically-dropping-and-creating-constraints.html