title: Entity Framework won't resolve PK-FK relationship with composite primary key?
body: <p>I'm trying to set up an EDM on an existing SQL Server infrastructure, and came across a problem.</p>
  
  <p>The EDM will <em>not</em> resolve a PK-FK relationship to a composite foreign key.</p>
  
  <p>My DB table structure looks something like this (names changed to protect the innocent):</p>
  
  <ul>
  <li>I have a PERSONS table containing an INT column called PerID (PK)</li>
  <li>I have an OFFICE table containing an INT column called OffID (PK)</li>
  <li>I am tying these tables together using a table called OFFICEPERSONS, creating a many-to-many relationship between PERSONS and OFFICE.  This table has two INT columns, PerID and OffID, which together form a composite primary key.</li>
  <li>I have a table called OFFICELOCATION that contains two INT columns, LocID and OffID.  These two columns comprise a composite primary key.  Additionally, OffID is also a FK to the OFFICE table.</li>
  <li>Finally, I have a table called OFFICEPERSONSLOCATION.  This table has three INT columns: PerID, OffID, and LocID.  All three columns comprise a composite primary key.  LocID and OffID provide a FK relationship to OFFICELOCATION, and OffID and PerID provide a FK relationship to OFFICEPERSONS.</li>
  </ul>
  
  <p>With me so far?  Hopefully, I haven't lost you yet.  When all is said and done, my structure looks like this:
  <img src="https://i.stack.imgur.com/qeZlh.png" alt="Database structure diagram"></p>
  
  <p>This structure works great in SQL Server.  In EDM?  Not so much.  It will NOT allow me to construct the relation between OFFICEPERSONSLOCATION and OFFICEPERSONS.  I get the following error:</p>
  
  <blockquote>
    <p>Error 6037: Foreign key constraint 'FK_OFFICEPERSONSLOCATION_OFFICEPERSONS' has been omitted from the storage model. Column 'OffID' of table 'Model.Store.OFFICEPERSONSLOCATION' is a foreign key participating in multiple relationships. A one-to-one Entity Model will not validate since data inconsistency is possible.</p>
  </blockquote>
  
  <p>Huh?  Data inconsistency?!?  How?</p>
  
  <p>How do I get my entity framework to recognize this?</p>