Entity Framework 4 - Use a single mapping table for all many-to-many relations

I would like to map all many-to-may relations through a single table in my database. Meaning that I have numerous tables (entities) that have various many-to-many relations. Instead of having a separate mapping table for every relation I would like to use one "master mapping" table having to columns: End1Id & End2Id.

Don't ask why ;) It's required by my customer...

How would I set this up in the model designer, or do I have to edi开发者_JAVA技巧t the edmx xml directly....or is it just not possible?

Thanx for your help!

In such a scenario you can't have explicit foreign keys, because a table like this normally has at least three rows:

1. PK of table 1
2. PK of table 2
3. Type of mapping, which specifies the exact tables to use.

Because of that, you can just create a table in EF, but it will also have no connections to other tables and you will have to do the joins manually.

You would need to set this Master Mappings table manually. The designer doesn't do it for you automatically.

However - if denormalized entities are what you are looking for, better have those denormalized in DB level rather than in EF/code level.