Re: How to change column type in PostgreSQL 7.1.2

alter table t add column newcolumn varchar(20);
update t set newcolumn = oldcolumn::varchar;
-- drop constraints / indexes
alter table t drop column oldcolumn;
alter table t rename newcolumn to oldcolumn;
-- create new constraints / indexes
vacuum analyze t;

/M

----- Original Message -----
From: "Williams, Travis L, NPONS" <tlw(at)att(dot)com>
To: "Vilson farias" <vilson(dot)farias(at)digitro(dot)com(dot)br>; <pgsql-general(at)postgresql(dot)org>
Sent: Thursday, June 12, 2003 3:56 PM
Subject: Re: [GENERAL] How to change column type in PostgreSQL 7.1.2

> I don't know about the primary key part.. what I do is create a table identical to the one I'm copying (minus index's, primary keys, stuff like that) and copy my data over.. verify the data was copied.. then drop the original.. recreate the original the way you want.. then copy the data back over.. and verify.. then drop the temp table..
>
> Travis
>
> -----Original Message-----
> From: Vilson farias [mailto:vilson(dot)farias(at)digitro(dot)com(dot)br]
> Sent: Thursday, June 12, 2003 7:54 AM
> To: pgsql-general(at)postgresql(dot)org
> Subject: [GENERAL] How to change column type in PostgreSQL 7.1.2
>
>
> Greetings,
>
> I'm wondering if there is a way to change a column type in PostgreSQL
> 7.1.2 without reconstruction of table + pg_dump/restore of table data
> (machine can't be stopped for a long time). I have a table with a integer
> column and I would like to change it to varchar(20). One more thing, this
> collumn belongs to a composed primary key. Is it possible?
>
> Best regards
>
> ----------------------------------------------------------------------------
> ----
> José Vilson de Mello de Farias
> Software Engineer
>
> Dígitro Tecnologia Ltda - www.digitro.com.br
> APC - Customer Oriented Applications
> E-mail: vilson(dot)farias(at)digitro(dot)com(dot)br
> Tel.: +55 48 281 7158
> ICQ 11866179
>
>
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