private static void ConflictingUpdateLastWins()
{
NorthwindEntities context = new NorthwindEntities();
Category newCategory = new Category()
{
CategoryName = "New Category",
Description = "New category, just for testing"
};
context.Categories.AddObject(newCategory);
context.SaveChanges();
// This context works in different transaction
NorthwindEntities anotherContext = new NorthwindEntities();
Category lastCategory =
(from cat in anotherContext.Categories
where cat.CategoryID == newCategory.CategoryID
select cat).First();
lastCategory.CategoryName = lastCategory.CategoryName + " 2";
anotherContext.SaveChanges();
// This will cause OptimisticConcurrencyException if
// Categories.CategoryName has ConcurrencyMode=Fixed
newCategory.CategoryName = newCategory.CategoryName + " 3";
context.SaveChanges();
}
private static void AddCategoriesInTransaction()
{
NorthwindEntities context = new NorthwindEntities();
// Add a valid new category
Category newCategory = new Category()
{
CategoryName = "New Category",
Description = "New category, just for testing"
};
context.Categories.AddObject(newCategory);
// Add an invalid new category
Category newCategoryLongName = new Category()
{
CategoryName = "New Category Loooooooong Name",
};
context.Categories.AddObject(newCategoryLongName);
// The entire transaction will fail due to
// insertion failure for the second category
context.SaveChanges();
}
/// <summary>
/// Create a new Category object.
/// </summary>
/// <param name="categoryID">Initial value of the CategoryID property.</param>
/// <param name="categoryName">Initial value of the CategoryName property.</param>
public static Category CreateCategory(global::System.Int32 categoryID, global::System.String categoryName)
{
Category category = new Category();
category.CategoryID = categoryID;
category.CategoryName = categoryName;
return category;
}
/// <summary>
/// Deprecated Method for adding a new object to the Categories EntitySet. Consider using the .Add method of the associated ObjectSet<T> property instead.
/// </summary>
public void AddToCategories(Category category)
{
base.AddObject("Categories", category);
}
