You are migrating a database named Orders to a new server that runs Microsoft SQL Server 2016. You attempt to add the [Corpnet\User1] login to the database. However, you receive the following error message: "User already exists in current database." You need to configure the [Corpnet\User1] login to be able to access the Orders database and retain the original permissions. You need to achieve this goal by using the minimum required permissions. Which Transact-SQL statement should you use?