Re: Delete Subquery
| From: | Chris Bolt | Date: | Mon, 14 Jun 2004 16:09:46 +0000 |
| Subject: | Re: Delete Subquery | ||
| References: | 1 | Groups: | php.db |
| Request: | Send a blank email to php-db+get-34782@lists.php.net to get a copy of this message | ||
How about:
DELETE FROM users WHERE userid IN (SELECT u.userid FROM users AS u
LEFT JOIN roles AS r ON (u.roleid = r.roleid) WHERE r.roleid IS NULL
LIMIT 1);
On Mon, 14 Jun 2004 11:59:25 -0400, Brock Jimmy D Contr 74 MDSS/SGSI
<jimmy.brock@wpafb.af.mil> wrote:
>
> I've been able to figure how to use a delete subquery to delete all rows, but how do I use
> a delete subquery to delete only one row?
>
> I have two tables: users and roles with the following fields:
>
> Users:
>
> userid
>
> roleid
>
> Roles:
>
> roleid
>
> I want to be able to delete a rowid from the roles table, but only if the roleid does not exist
> in the users table.
>
> thanks
>
>