Question

In a table I have a field that stores users who are allowed to see a post. I have something like 93849038,39480398 where the commas separates the users.

So this is what I am trying to do:

$user = logged in user; example: 93849038.

And this is what my query looks like:

 $sql = "SELECT note FROM notes_are WHERE user_allowed = '$user' ORDER 
 BY id DESC LIMIT 0, 3";

Using a structure like that I am unable to serve the post.

Answer 1

This is not a recommended practice as it forces the database engine to inspect all rows of your table. It’s better to create a permission table where each user that has access to a note are listed separately (make sure to also index the user column).

If you really REALLY have to, you can use the LOCATE string function (assuming MySQL): http://dev.mysql.com/doc/refman/5.5/en/string-functions.html#function_locate

Of course, LOCATE has issues too because it doesn’t care about comma delimited stuff, so the “better” approach might be REGEXP: http://dev.mysql.com/doc/refman/5.5/en/regexp.html#operator_regexp