Querying and updating a database table
Now that we have
the entity classes created, we will use them to interact with the database. We will first work with the
products table to query and update records as well as to insert and delete records.
First we will query the database to get some products.
To query a database by using LINQ to Entities, we first need to construct a
DbContext object, as follows:
NorthwindEntities NWEntities = new NorthwindEntities();
We can then use the LINQ query syntax to retrieve records from the database:
IEnumerable<Product> beverages = from p in NWEntities.Products where p.Category.CategoryName == "Beverages" orderby p.ProductName select p;
The preceding code will retrieve all of the products in the