Visual Basic 2015 Unleashed

Updating Entities

Updating existing entities is even easier than adding new ones. First, you need to obtain the instance of the entity you want to update. When you get the instance, you edit its properties and then invoke the DataContext.SubmitChanges method. The following code provides an example:

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Sub UpdateProduct(ByVal productInstance As Product)    'Throws an exception if a null value is passed    If productInstance Is Nothing Then        Throw New NullReferenceException    Else        With productInstance            .ProductName = "Italian Linguine"            .UnitsInStock = 100        End With    End If    SaveChanges()End Sub

This method requires an instance of the Product entity to be updated. To get an ...