Transaction Processing on MySql

• Supported only for INNODB tables!
• By default, each mysql statement is automatically committed, i.e. made a permanent part of the database. There are two ways to change this default behavior in MySql:
  • You can turn this behavior off by SET AUTOCOMMIT = 0. Note: That is a zero. 
  • If autocommit is off,  all changes have to be explicitly committed, using the commit command. Only then do the changes become a permanent part of the database.
  • Issuing a rollback command, instead of a commit, undoes all the changes made to the database since the previous commit.
  • Or, you can leave AUTOCOMMIT unchanged, and issue a START TRANSACTION command, which starts a transaction. 
    • All changes made to the database during the transaction are tentative and can either be:
    • undone with the rollback command.
    • or made permanent with the commit command.
    • Either of those commands ends the transaction