Re: A mysql question...
| From: | Richard Quadling | Date: | Thu, 21 Oct 2010 13:46:27 +0000 |
| Subject: | Re: A mysql question... | ||
| References: | 1 | Groups: | php.general |
| Request: | Send a blank email to php-general+get-308932@lists.php.net to get a copy of this message | ||
On 21 October 2010 14:13, Midhun Girish <midhungirish@gmail.com> wrote:
> | Name | phone |userid|
>
> +------------+--------------+------+
>
> | Mr Sasi | 01225 708225 | 1 |
>
> | Miss Brown | 01225 899360 | 2 |
>
> | Mr Black | 01380 724040 | 3 |
>
> +------------+--------------+------+
> Table B
>
> +------------+--------------+
>
> | blockedbyid| blockedid |
>
At first glance ...
SELECT
A.UserID,
A.Name,
A.Phone
FROM
A
WHERE
A.UserID NOT IN
(
SELECT
B.BlockedID
FROM
B
WHERE
B.BlockedByID = x
)
The Subselect finds all the user ids blocked by x.
The main select finds all users who are NOT in the subselects list.
I'm pretty sure a subselect isn't as efficient as it could be though.
--
Richard Quadling
Twitter : EE : Zend
@RQuadling : e-e.com/M_248814.html : bit.ly/9O8vFY