System data updateexception an error occurred while updating the entries
After you have executed the code, you can go ahead and physically verify the record in the database.If the query executed successfully, you should see a new record in the Customers table of the Northwind database, as shown below: Update Objects in Entity Framework 4.0 As I mentioned earlier, objects attached to the object context are managed by that object context.Objects attached to the object context are managed by that object context. Observe the code shown below: All we are doing here is create a new instance of the Customer type and populate its properties.
When Add Object() is called, a temporary Entity Key is generated and the Entity State is set to 'Added', as shown below: When context.Save Changes() is called, EF 4.0 goes ahead and inserts the record into the database.The steps to update an existing entity are quite simple.First retrieve an instance of the entity from the Entity Set), then edit the properties of the Entity and finally call Save Changes() on the context.
We will be using the same console application that we created in the previous article, so make sure you have read the previous article before we continue.
We will be adding three methods to the console application: add Customer(), delete Customer() and modify Customer() Create and Add Objects in Entity Framework 4.0 In order to add new objects to the Entity Set, you must create an instance of an Entity type and add the object to the object context.