On 21 October 2010 14:13, Midhun Girish <midhungir...@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

-- 
PHP General Mailing List (http://www.php.net/)
To unsubscribe, visit: http://www.php.net/unsub.php

Reply via email to