title: Another Many-Many Scenario
body: <p>My database model has 2 particular tables in it that require a many-to-many relationship. The tables are <code>Systems</code> and <code>Users</code>. One user can be a member of more than one system and one system has more than one user in it. </p>
  
  <p><code>system_id</code> is the PK in the system table and <code>user_id</code> is the PK in the user table. I have them linked with <code>system_id</code> as a FK in the user table. I can't seem to figure out a table in between the two. I had the notion of forming a <code>system_user</code> table and using both foreign keys in there but cant see how that would work.</p>