SQL Databases, Entity Data Models and 1 to 1 entities

Question

I am quite new to EDMs, having written quite a lot of ADO.Net stuff in the past. I have three tables:

**Product:**
Prod_ID - PK

**Product_MaxLoan**
Prod_ID - PK

**Product_MinLoan**
Prod_ID - PK

These tables, hosted in MS SQL 2005, have no FKs or constraints configured as yet, they are to have a notional 1 to 1 relationship. For example, every row of a Product with ID of 1, there will be a row in Product_MaxLoan and Product_MinLoan each with an ID of 1.

In Visual Studio 2010, I want to set the EDM up correctly so that the cardinality is set to 1 to 1. I previously had FK constraints on the tables and the following set up, however, this would only allow a 0..1 cardinality (to cater, I suppose, for the fact a Product may not have a Product_MaxLoan or Product_MinLoan).

**Product:**
Prod_ID - PK

**Product_MaxLoan**
ID - PK
Prod_ID - FK

**Product_MinLoan**
ID - PK
Prod_ID - FK

Questions:

• What advice would you give for setting these tables up in SQL 2005? For a 1 to 1 relationship in an EDM would you set up FKs?
• Can you set up a PK relationship in SQL 2005 that the EDM will read when importing from a database?
• A product contains some 300 properties, so containing all of this data in a single table would be poor database normalization (hence the many 1 - 1 tables). Would best practice be to put all of these properties into a single EDM class? My gut reaction is to break it down much as it is structured in the DB (this is my ADO heritage coming to the fore), having a class for each logical part of the product.

Your advice would be appreciated.

Best regards,

Mark