Do you know that, Windows Phone 7.1 (Mango) now supports local database? Yes, you can now use local database inside your Phone 7 device and use it to CRUD operations. You can now create a DataContext class from an existing database and use it as the entry point class to do DB operation.   In this chapter we will learn how to create a DataContext class for local SQL CE database. At the end of this tutorial our data context class will be ready for further DB operations.   Index - Windows Phone 7 (Mango) Tutorial   Download SQL CE Database File Before creating the DataContext file, you need an existing SQL CE database file. We will use "Northwind" database to demonstrate it. You can download the "Northwind.sdf" file from here: Download Northwind Database File for SQL CE (1,560 KB) This database file comes with Visual Studio installation. If you already installed Visual Studio 2010 in your PC, you can get it from the...