Re: adding column with not null constraint - Mailing list pgsql-sql

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Subject Re: adding column with not null constraint
Date
Msg-id 1253.203.145.130.142.1034978261.squirrel@mail.trade-india.com
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In response to adding column with not null constraint  (Vivek Khera <khera@kcilink.com>)
List pgsql-sql
Hi Vivek,

In 7.3 there  will be a fully implemented ALTER TABLE command for making
columns null or not null.

Currently you can update 'attnotnull' of pg_attribute system catalog
for the attrelid and attname. use pg_class system catalog for getting
attrelid of a given relation.

Regds
MAllah.

> I'm looking to add a column to my database with not null and a default value:
>
> vk=> alter table msg_owner add column user_optional_fields varchar(255) NOT NULL default '';
> ERROR:  Adding columns with defaults is not implemented.
>        Add the column, then use ALTER TABLE SET DEFAULT.
> vk=> alter table msg_owner add column user_optional_fields varchar(255) NOT NULL ; ERROR:
> Adding NOT NULL columns is not implemented.
>        Add the column, then use ALTER TABLE ADD CONSTRAINT.
>
> Ok, so we can succeed with this:
>
> ALTER TABLE msg_owner ADD COLUMN user_optional_fields VARCHAR(255); ALTER TABLE msg_owner ALTER
> user_optional_fields SET DEFAULT '';
> UPDATE msg_owner SET user_optional_fields = '';
>
> Now my problem is I cannot find any syntax for ALTER TABLE ADD
> CONSTRAINT to put a NOT NULL constraint on a column.  Can someone help me here?
>
> I'm using Postgres 7.2.1 on FreeBSD 4.6.
>
> Thanks.
>
> --
> =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= Vivek Khera, Ph.D.
>         Khera Communications, Inc.
> Internet: khera@kciLink.com       Rockville, MD       +1-240-453-8497 AIM: vivekkhera Y!:
> vivek_khera   http://www.khera.org/~vivek/
>
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