What is rollback in sql?

Answer by  mandriloquai (324)

Rollback is an operation which returns a database transaction to a previous state. Most DBMS (Data Base Management Systems) have auto commit enabled, which means that the current data management operation is saved or committed. To explicitly begin a transaction, we need to declare it (BEGIN TRANSACTION) and rollback if we do not wish the changes to be saved.

Answer by  knightmare (1231)

A ROLLBACK command will restore a database to how it appeared before the last COMMIT command. Say you insert 10 rows into a table, COMMIT, insert 20 rows into a table, and do a ROLLBACK. The 10 rows you first inserted will be there but the 20 other rows will not. ROLLBACK is good for testing among other things.

Answer by  ardentblarney (32)

A rollback in sql is a command statement that is used to partially cancel or fully cancel an entire transaction

Answer by  pbako (96)

Rollback allows you to undo a write to a database. Used when multiple transactions all have to occur, or none are allowed to occur.