Question

in MySQL, I have a row for each user, with a column that contains friends names separated by \n.

eg.
Friend1
Friend2
Friend3

I’d like to be able to quickly search all the users where the Friends field contains Friend2.

I’ve found FIND_IN_SET but that only works for commas and the data can contains commas and foreign characters.

Obviously searching with regular expressions and the such will be slow. I’m new to the whole cross referencing so I’d love some help on the best way to structure the data so that it can be found quickly.

Thanks in advance.

Edit: Ok, I forgot to mention a point that the data is coming from a
game where friends names are stored locally and there are no links to
another users ID. Thus the strings. Every time they connect I am given
a dump of their friends names which I use in the background to help match games.

Answer 1

The most commonly used structure for this kind of data is usually adding an extra table. I.e.

user
    id,
    name
    email,
    e.t.c.

user_friend
    user_id
    friend_id

Querying this is a matter of querying the tables. I.e.

List all of a users friends names:

SELECT friend_id
FROM user_friend 
WHERE user_id = :theUser

Edit: Regarding OPs edit. Just storing the names is possible too. In this case the table structure would become:

user_friend
    user_id
    friend_name

and the query:

SELECT friend_name 
FROM user_friend 
WHERE user_id = :theUser