Explain NOT NULL constraint in SQL Server.

The NOT NULL constraint is used not to accept NULL values in a column. This makes sure to add values at the time of adding and updating the records.

Ex :

Create Table Suppliers

(

Supplier_ID int NOT NULL,

Supplier_Name varchar (300) NOT NULL,

Address varchar (500),

City varchar (200)

)

This Query will make sure the “Supplier_ID” and “Supplier_Name” columns to not accept NULL values.