Question

I’m working on a small project that involves grabbing a list of contacts which are stored for each group. Essentially, the database is set up so that each group has a primary and secondary contact stored as, unsurprisingly, Group.Primary and Group.Secondary. The objective is to pull every Primary and Secondary contact for each Group and display them in a sortable table.

I have the sortable table all worked out, but I have come across a small problem. Each primary and secondary field can have more than one contact separated by a comma. For instance, if Primary contained 123,256 , it would need to pull both Contacts with IDs 123 and 256. I had intended to use a query formatted like this:

SELECT * 
  FROM Group G, 
       Contacts C 
 WHERE G.Primary LIKE %C.ID% 
    OR G.Secondary LIKE %C.ID%

so that I could just skip the comma part, but I can’t seem to find a working query for this.

My question to you is, am I just overlooking something here? Is there a simple query that would let me do this? Or am I better off getting the groups and contacts separately, and combine the two later. I think the former is a little easier to understand when read, which is a plus as this is a shared project, but if that is not possible I will do the latter.

This code is simplified, but it gets the point across.

Answer 1

If I understand correctly, you want to use the MySQL FIND_IN_SET function:

SELECT * 
  FROM Group G 
  JOIN Contacts C ON FIND_IN_SET(c.id, g.primary)
                  OR FIND_IN_SET(c.id, g.secondary)

But I highly recommend you normalize the table — do not store comma delimited lists if at all possible.