Question

I have 2 tables.

First table is called professions, and those are indexed by ID. So each profession now has a unique ID associated with it.

My second table is called contacts, and in there I have a profession field that right now only hold the ID that a certain profession is associated with.

My problem is that what if I have a contact that has more than one profession associated with it.

What would be the best way to query the table and ways to store the professions of a contact. I didn’t want to do is create a field to just store a 0 or 1 int for each profession I have. The reason is because I want to dynamically grow the professions table and have the numbers reflect any dynamic changes on my site when I query.

Answer 1

You have a many-to-many relationship. To implement that in MySQL you should use a linking table. So professions and contacts should have an id in each table, but no foreign keys, and you create a new table called profession_contact_links or something, containing its own id, and profession_id and contact_id, which are both foreign keys to the respective tables. Then you can have many contacts linked with each profession, and many professions linked with each contact. To connect the two main tables together in a select you will need two joins, and what they are will depend on what exactly you want to select.