10. mysql transaction Introduction

10. mysql transaction Introduction

1. myisam and memory support table-level locking BDB page-level locking Innodb row-level locking 2. table lock (not a table) lock table read // read-only table lock, that is, after the lock is executed, the operation in the lock can only be read operation select * from ..... unlock tables; lock table write // read/write table lock, readable and writable insert... update... select... delete... unlock tables; PS: after the table is locked, other connection operations will be suspended until the locked connection is unlocked. If the TM remains unlocked, it will be finished !!! 3. transaction begin | start transaction rollback | commit submit transaction PS: If you are executing a mysiam table Lock operation, but you have enabled the transaction during the table Lock operation, the lock will be unlocked.

 

What is a mysql database transaction? create table xxxx (...) engine innoDB when creating a table; a statement indicates that innoDB supports transactions when creating an engine.
Start transaction: start transaction;
Write an SQL statement as long as the transaction is not committed, there is a commit explicit commit, and implicit commit. If the SQL statement is not written properly, commit and commit the transaction; A problem occurs in the preceding SQL statement, which means that Rollback is more than a batch change of coins in a SQL statement. Rollback means that when the transaction is started, the status indicates that the SQL operation of the transaction is enabled, and the transaction has not been restarted.
Note: When the transaction commit or rollback ends
Mysql transaction processing? Disable Automatic submission insert data temporarily written into database reserved temporary region submission