Row Locking

BEGIN TRAN

SELECT *
FROM authors
WITH (HOLDLOCK, ROWLOCK)
WHERE au_id = '274-80-9391'

/* Do all your stuff here while the record is locked */

COMMIT TRAN

The HOLDLOCK hint will instruct SQL Server to hold the lock until you commit the transaction. The ROWLOCK hint will lock only this record and not issue a page or table lock.

The lock will also be released if you close your connection or it times out. I'd be VERY careful doing this since it will stop any SELECT statements that hit this row dead in their tracks. SQL Server has numerous locking hints that you can use. You can see them in Books Online when you search on either HOLDLOCK or ROWLOCK.