EF4 a table is divided into multiple entities

 If we have a table that contains some frequently used fields and some very large but not frequently used fields, we should avoid reading these fields during queries for performance reasons.

In this case, we can split a table into two or more entities.

 In the following example, the person table contains personal and family information. To split personal and family information, follow these steps:

1. Add the person table to EDM.

 

2. Add an object type. The object name is personfamilyinfo. Change the key property name to personid.

 

 3. Cut the family information in the person object to the personfamilyinfo object..

4. ClickPersonfamilyinfoTo view the Mapping Details window, clickAddA table or view, select object person

 

 5. Right-click the person object and add a one-to-one association to personfamilyinfo.

 

6. View Association attributes and add a reference constraint between two entities to ensure that personfamilyinfo does not exist independently of person.

In this way, we split a table into two entities: