Appendix B: LINQ to Entities: The ADO.NET Entity Framework
ADO.NET Entity Framework addresses a number of developer issues that have been around for a while.
For some time, developers have been struggling with how to model entities and relationships and at
the same time work with the relational databases that store the data they need. It gets more difficult
if the data spans multiple data stores. Add the OO layer to this puzzle, and you have the complexity of
using OO technology to map to relational data stores, yet at the same time trying to make it easy (more
efficient) for the developer.
For example, you can model a class to a relational data table, but how often is that a one-to-one situation?
Typically, you have multiple tables that are mapped to a single class??”and how do you represent
relationships? Relationships between classes are certainly not the same as relationships between tables.
You also have the problemof connecting objects with the data, meaning, how do you connect OO systems
to relational data?
The good news is that the ADO.
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