i have a table named post which contains a postid field and a userid field and another one table named announcement with a postid field which is being fed by that of post's postid.
The problem is that i cannot select the rows from the announcement table for a specific userid of the table post
here is my attempt
SELECT * FROM announcement a LEFT JOIN post p ON a.postid = p.postid AND p.userid='$user_id' WHERE p.postid is null ORDER BY postid DESC
Any help would be appreciated
