Assignment Details
The company has asked you to build a prototype of an n-tier system using the Northwind database as an example. The company wants to be able to add, edit, and delete records from the customers, orders, order details, products, categories, and suppliers tables. Your instructor will provide you the online link to the SQL Server database files (MDF and LDF).
Use this link:
Database scripts can be found in 
https://docs.microsoft.com/en-us/dotnet/framework/data/adonet/sql/linq/downloading-sample-databases
Click on Northwind and pubs sample database for Microsoft SQL Server
and download file instnwnd.sql
Run script in Visual Studio to create the database
Assignment Guidelines

Create the Data Access tier and Data tier projects:

Create a class library project for the Data tier.
Add a new class library project the project created in Step 1 for the data access tier.
Add a typed DataSet using a new data source that connects to the Northwind sample database.
Select the database objects (customers, orders, order details, products, categories, and suppliers) tables.
Make sure the TableAdapters are stored in the Data Access tier and the DataSet class is added to the Data tier.

Make sure that separate tiers are created for each layer by verifying that separate class libraries were created and the necessary references to the project were added.