Getting Changes that Will be Performed During the Next Commit

This article is relevant to entity models that utilize the deprecated Visual Studio integration of Telerik Data Access. The current documentation of the Data Access framework is available here.

The OpenAccessContext.GetChanges method returns all objects that will be inserted, updated or deleted during the next commit. In the following example, a LINQ query returns a single Category object based on a specified CategoryName. Then, the Description property of the category is changed, two new category objects are added to the context, and the newly added items are deleted. The GetChanges method is called to get all pending inserts, deletes or updates.

using (EntitiesModel dbContext = new EntitiesModel())
{
   // Update a category
   Category category = dbContext.Categories.First();
   category.CategoryName = "New Name";

   // Create two new categories
   Category newCategory1 = new Category();
   newCategory1.CategoryName = "New Category";
   Category newCategory2 = new Category();
   newCategory2.CategoryName = "New Category2";

   dbContext.Add(new Category[] { newCategory1, newCategory2 });

   dbContext.Delete(new Category[] { newCategory1, newCategory2 });

   // GetChanges
   Telerik.OpenAccess.ContextChanges contextChanges = dbContext.GetChanges();
   IList<Category> inserts = contextChanges.GetInserts<Category>();
   IList<Category> updates = contextChanges.GetUpdates<Category>();
   IList<Category> deletes = contextChanges.GetDeletes<Category>();

   Console.WriteLine("{0} objects will be inserted", inserts.Count);
   Console.WriteLine("{0} objects will be updated", updates.Count);
   Console.WriteLine("{0} objects will be delete", deletes.Count);
}

Using dbContext As New EntitiesModel()
 ' Update a category
 Dim category_Renamed As Category = dbContext.Categories.First()
 category_Renamed.CategoryName = "New Name"

 ' Create two new categories
 Dim newCategory1 As New Category()
 newCategory1.CategoryName = "New Category"
 Dim newCategory2 As New Category()
 newCategory2.CategoryName = "New Category2"

 dbContext.Add(New Category() {newCategory1, newCategory2})
 dbContext.Delete(New Category() {newCategory1, newCategory2})

 ' GetChanges
 Dim contextChanges As Telerik.OpenAccess.ContextChanges = dbContext.GetChanges()
 Dim inserts As IList(Of Category) = contextChanges.GetInserts(Of Category)()
 Dim updates As IList(Of Category) = contextChanges.GetUpdates(Of Category)()
 Dim deletes As IList(Of Category) = contextChanges.GetDeletes(Of Category)()

 Console.WriteLine("{0} objects will be inserted", inserts.Count)
 Console.WriteLine("{0} objects will be updated", updates.Count)
 Console.WriteLine("{0} objects will be delete", deletes.Count)
End Using