mySql - creating a join using a list of comma separated values

Question

I\'ve got a table with a field for Merchant\'s name and field with the Services they provide. The Services field is a comma separated list of integers that relate to another

Answer 1

The short term solution to your issue is to use the FIND_IN_SET function to join the MERCHANT and SERVICES tables:

SELECT *
  FROM MERCHANT m
  JOIN SERVICES s ON FIND_IN_SET(s.service_id, m.services) > 0

The long term solution is to correct your tables - never allow columns to contain comma separated lists of referential ID/etc values.