The following code will restore a database from a backup file in MS SQL Server. Normally you would use Management Studio to do this, but this might fail if the database needs to be in single user mode to restore. The code below will restore the database as a single user, then put it back in multi-user mode after its done.
—[ Transact-SQL Code ]——————–
-- Set database as single user and restore from backup.
ALTER DATABASE <your_database> SET SINGLE_USER WITH ROLLBACK IMMEDIATE
RESTORE DATABASE <your_database> FROM DISK = 'D:\Databases\YourDatabase.bak' WITH REPLACE
-- Set database back to multi user.
ALTER DATABASE <your_database> SET MULTI_USER WITH ROLLBACK IMMEDIATE GO