Question

I need to make a query from a column that contains a strings that looks like this:
Language1, Language2, Language3.

I can not really create a new column for each of the language as their is an undefined number of them.

So i am wondering what would be the most performant / elegant way to query data from within that string?

Should i use serialized data ? What would a query that retrieves all rows that matches lets say “Language2”?

EDIT
This table holds an index of criteria that i use to search users from my site. Language is one of the criteria, so will be city, country and a bunch of others. Problem is that each user can have an undefined number of languages.

Second Edit
Here is a view of my table as it is right now:

Answer 1

No, you should normalize your table schema. Yes, you can even cope with the undefined number of values.

Make a separate table that will hold the relationship references.

table_languages

ref_id | language

---

Sample data would be:

user_id | language
-------------------
   1   | Language 1
   1   | Language 2
   1   | Language 3
   2   | Language 2

---

Sample query would be:

    SELECT *
      FROM users u
INNER JOIN languages l
        ON u.user_id = l.user_id
       AND l.language = 'language2'
     WHERE u.country = 'abc'
       AND u.city = 'def';