How to have more than 1 M-M relationship in EF4
===

My problem is simple but I can't seem to get EF to understand my database schema (Oracle).

**Problem**

I want to model **more than 1** M-M relationship see diagram below:

![enter image description here][1]

As you can see I have a book and a journal - and I want to store a URI against both of these, by way of using a linking table (junction table, intersection table, you get it!).  In this case it happens to be "www.google.com" that I want to store against Journal 16 and Book 75, they would be stored in the linking table in the follwoing format marked out in blue.  For completeness I have added a green example for link with an ID of 5.
So you can see how the data knits together, I think you'll agree it's nothing too crazy.

Anyway, when I try and update EF model, it complains (in Visual Studio) with an error along the lines of.


> Problem in mapping fragments starting at line 210:Foreign key
> constraint 'REF_URI_JOURNAL_FK1' from table REF_URI (REF_ID) to table JOURNALs (REF_ID): > The columns of table REF_URI are mapped to AssociationSet BOOK_URISet's End BOOK> but the > key columns of table JOURNAL are not mapped to the keys of> the EntitySet BOOK corresponding to this End.

Yeh - not really getting that error message!
I can get EF to work with 1 M-M relationship, e.g.

![enter image description here][2]

and it all works "hunky dory", but when I added a second M-M relationship it fell over with that error message above e.g.

![enter image description here][3]

Anyone know how I can get round this?


  [1]: http://i.stack.imgur.com/EjaS2.png
  [2]: http://i.stack.imgur.com/xeCky.png
  [3]: http://i.stack.imgur.com/SoHXQ.png