Using LINQ to Entities in the data access layer
Next, we will modify the data access layer to use LINQ to Entities to retrieve and update products. We will first create GetProduct
to retrieve a product from the database and then create UpdateProduct
to update a product in the database.
Adding a reference to the BDO project
Now that we have the BDO project in the solution, we need to modify the data access layer project to reference it.
In the Solution Explorer, right-click on the NorthwindDAL project.
Select Add | Reference....
Select the NorthwindBDO project from the Projects tab under Solution.
Click on the OK button to add the reference to the project.
Creating GetProduct in the data access layer
We can now create the GetProduct
method in the data access layer's class, ProductDAO
, to use LINQ to Entities to retrieve a product from the database. Just as we did in the previous chapter, we will first create an entity DbContext
object and then use LINQ to Entities to get the product from the DbContext...