Professional Visual Basic® 2010 and .NET 4

Chapter 11. Data Access with the Entity Framework

WHAT YOU WILL LEARN IN THIS CHAPTER

• What is Object-Relational Mapping?

• What is the Entity Framework

• How the Entity Framework works with databases

• Using the Entity Framework to edit data

• Using the Entity Framework to create new databases

In the past, Microsoft has been known to change the recommended data access strategy relatively frequently. For example, Data Access Objects (DAO) was released in the Visual Basic 3.0 time frame, followed by RDO (Remote Data Objects) as an option in the Visual Basic 4 days, and ADO (Active Database Objects) with Visual Basic 6. Of course, all of these were COM libraries, so it was no surprise when they were superseded by ADO.NET when the .NET Framework shipped. There have been remarkably few changes to ADO.NET since then.

Now, when I see Microsoft recommending a new data access strategy, I start to get nervous. However, in this case there is good news. The Entity Framework (EF) does not replace ADO.NET. You can continue to use ADO.NET without fear of it going away, even as a recommended data access tool. The Entity Framework simply provides a different — richer and more flexible — model for working with data sources.

Beyond simply being a set of classes you use to access your data, Entity Framework enables you to work naturally with the data using the classes you have designed, while saving the data to the underlying database schema. The Entity Framework provides the mapping necessary to convert the data ...