Storing and selecting multiple ids in database

I have a newsletter component and users can subscribe to multiple newsletters. It is stored in the table of the subscribers like this: 4,8,11 (these are the id's of the newsletters the subscriber is subscribed to)

To select the subscribers of a newsletter I use:

"SELECT * FROM #__newsl_subscribers WHERE newslids LIKE '%" . (int) $id."%'";

When I want to select all users that rec开发者_运维知识库eive newsletter with id 1, the user that receives newsletter 11 (or 12, 10 etc..) is also selected. And that's the problem.

Is there a select-statement for this? Otherwise I have to store the id's with brackets around them [1],[11], etc...

You really should avoid solutions where several ids are stored in one field. Instead you should use foreign keys and, like in your case for n:m relationships, relationship tables. n:m-relationships are these where a can have multiple b and vice versa.

I would do the following:

Table "subscriber": No information about newsletters

Table "newsletter": No information about subscribers

New table "newsletter_subscriber":
Field: subscriber_id
Field: newsletter_id
Both fields are foreign keys (references to the primary key of another table).

To select all subscribers of a specific newsletter, you can use this statement:

SELECT s.* FROM subscriber s
INNER JOIN newsletter_subscriber ns ON ns.subscriber_id = s.id
WHERE ns.newsletter_id = <newsletter id>

And vice versa, to select all newsletters of a specific subscriber:

SELECT n.* FROM newsletter n
INNER JOIN newsletter_subscriber ns ON ns.newsletter_id = n.id
WHERE ns.subscriber_id = <subscriber id>

BTW I should appologize for not answering your original question. Maybe you know everything about database normalization, having other reasons for these ids stored in one field?