Purpose of EF 6.x DbContext Generator option when adding a new data item in Visual Studio

c# asp.net entity-framework linq linq-to-sql
frenchie picture frenchie · Apr 1, 2014 · Viewed 42.5k times · Source

I have a web app that I built using LINQ to SQL and I'm looking to upgrade it to LINQ to Entity Framework. I've looked at some tutorials and what I've learned is that basically in the database-first scenario, you create an ADO.NET Entity Data Model. And from there, you select which tables to include in the model (very similar to LINQ to SQL).

Within the Add New Item dialog, I see that there is another option that creates an EF 6.x DbContext Generator:

Visual Studio Add New Item dialog

What is the purpose of EF 6.x DbContext Generator compared to ADO.NET Entity Data Model (first option in dialog)? And, what is EF 6.x DbContext Generator for? It seems to create a text file. What should I do with it?

Answer

William Smith picture William Smith · Apr 13, 2014

The DbContext Generator replaces the ObjectContext with much simpler and shorter code to connect Entity objects to database objects. A single database table with 30 fields is represented by about 800 lines of code as an ObjectContext but about 40 lines of easy to understand code as a DbContext and class generated by the DbContextGenerator.

The DbContext Generator creates two files -

  1. creating the DbContext with connection string details and a DbSet for each table.

  2. creating the class representing each table. If you open these .tt folders you will see the DbContext and classes generated. You don't need to do anything with these classes - you refer to them in the Controller actions.

A walkthrough is available at http://msdn.microsoft.com/en-US/data/jj206878

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