Re: Evolving databases (eg deleting columns)

You'll also have to recreate any triggers/referential integrity constraints

On Saturday 27 July 2002 10:20 pm, you wrote:
> On Thu, 2002-07-25 at 20:19, Christian H. Stork wrote:
> > My question: How can I evolve databases (ie deleting columns,
> > adding/changing/removing constraints, etc)?
>
> PostgreSQL doesn't support deleting columns (I've had this issue myself
> recently).  However, there is a workaround.  It is described at:
> http://postgresql.org/docs/faq-english.html#4.4
>
> It states:
>
>
> 4.4) How do you remove a column from a table?
> We do not support ALTER TABLE DROP COLUMN, but do this:
>
>     BEGIN;
>     LOCK TABLE old_table;
>     SELECT ...  -- select all columns but the one you want to remove
>     INTO TABLE new_table
>     FROM old_table;
>     DROP TABLE old_table;
>     ALTER TABLE new_table RENAME TO old_table;
>     COMMIT;
>
> I hope this helps.

--
Regards,
Oliver

GT webMarque
+44(0)1792 655968 / 07808 678244 / oliver@gtwebmarque.com

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