Linq submitchanges not updating

01 Mar

Execute the code and go ahead and check the record in the database: Delete Objects in Entity Framework 4.0 To delete an existing record, retrieve an instance of the entity from the Entity Set. When the Delete Object() method is called, the Entity State of the object is set to ‘Deleted’ Finally call Save Changes() on the context to delete the data from the data source.

Another way to delete an object is to use the Object Context. Delete Object for our example Go ahead and check the database and you will find that the Customer ID=DNC no more exists.

Note that Entity Framework converts our code into queries that the database understand and handles all data interaction and low-level details.

Also notice in the code above, that we are accessing data as objects and properties.

When we do this LINQ to SQL will automatically create Dinner and RSVP classes using the schema of the tables (with class properties that map to the database table columns): By default the LINQ to SQL designer automatically "pluralizes" table and column names when it creates classes based on a database schema.

For example: the "Dinners" table in our example above resulted in a "Dinner" class.

After you have executed the code, you can go ahead and physically verify the record in the database.

Save Changes() is called, EF 4.0 goes ahead and inserts the record into the database.

The entire source code of this article can be downloaded over here.

This is step 3 of a free "Nerd Dinner" application tutorial that walks-through how to build a small, but complete, web application using ASP. Step 3 shows how to create a model that we can use to both query and update the database for our Nerd Dinner application. NET MVC 3, we recommend you follow the Getting Started With MVC 3 or MVC Music Store tutorials.

We can use the LINQ language support within VB and C# to write expressive queries that retrieve Dinner and RSVP objects from the database.

This minimizes the amount of data code we need to write, and allows us to build really clean applications.