Granting a SQL Server Login Access to a Database
Add a Microsoft® SQL Server™ user account to each database for each SQL Server login that requires access to the database. If a user is not created in the database, the SQL Server login cannot access the database.
To grant a SQL Server login access to a database, the SQL Server login must already exist. Furthermore, SQL Server logins must be granted access to a database one at a time.
To grant a SQL Server login access to a database
Transact-SQL