title: multiple constraint keys
body: <p>if i have tabled:</p>
  
  <ul>
  <li>Resource (id (PK), name)</li>
  <li>Manager (id(PK), resource_id (FK), manager_resource_ID(FK))</li>
  </ul>
  
  <p>Should resource_id and manager_id both be foreign keys into the <strong>Resource</strong> table.</p>
  
  <p>i obviously dont want to enter any values in each of those columns that are not proper resources</p>
  
  <p>when i add the first relationship (resource_id &lt;-> id) it works fine but</p>
  
  <p>when i add the second one (manager_resource_id &lt;-> id) it fails with the error:</p>
  
  <p><strong>Unable to create relationship [ . . .]    The ALTER TABLE statement conflicted with the FOREIGN KEY constraint [... ]. The conflict occured in table Resource, column id</strong></p>
  
  <p>or do i need to break this out into 3 tables?</p>
  
  <p>Resource(id, first, last)<br>
  Resource_manager(id, resource_id, manager_ID)<br>
  Manager(id)</p>