Is there a way to use EF4 to map a column to multiple tables?

I have the need to reduce the number of tables in the database being used as the base for Entity Framework 4.0.  So we need to use a single the activity table, for example, even though there are four tables which have entities: Manager, Employee, Department and Division.

The activity table holds the activity_id and activity_description for those four categories even though they have nothing in common.  So we are trying to use EF4 to have a single column point to any of four tables, differentiated only by their foreign keys.

Here are sample primary keys for the 4 tables.
MAN2011001
EMP2011001
DPT2011001
DIV2011001

Is there a way for EF4 to know that the MAN2011001 is a foreign key to the Managers table?

I am having a hard time with this test since it seems like this will NOT be a normalized database.

Please chime in.

Thanks,
newbieweb
curiouswebsterSoftware EngineerAsked:
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Bob LearnedCommented:
1) Entity framework should support modeling, which doesn't necessary have to strictly adhere to the database structure.

2) The Entity Data Model creates an abstraction from the database structure.

3) The Entity Framework supports inheritance and complex types:

• Inheritance: entity types can be defined so they inherit from other types (e.g. Employee could inherit from Contact). This kind of inheritance is strictly structural, meaning that there is no "behavior" inherited as it happens in object-oriented programming languages. What's in inherited is the structure of the base entity type; in addition to inheriting its structure, a instances of the derived entity type satisfy the "is a" relationship when tested against the base entity type.

• Complex types: in addition to the usual scalar types supported by most databases, the EDM supports the definition of complex types and their use as members of entity types. For example, you could define an Address complex type that has StreetAddress, City and State properties and then add a property of type Address to the Contact entity type.

Reference:

The ADO.NET Entity Framework Overview
http://msdn.microsoft.com/en-us/library/aa697427(VS.80).aspx

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curiouswebsterSoftware EngineerAuthor Commented:
Thanks.
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