If you do not need to filter the table in any of this fields (SQL "where" and "having" clauses), aggregate or join other tables using some values of this field you could safely use the string split/join solution.

If you need to manipulate individual values in SQL you could go in 2 ways:

• the suggested row based representation
• Look for arrays. I am not sure that MySQL have array fields but most of the DBMS I have experience with have some sort of array support (Oracle, Postgresql)