mysql的事務運作

mysql的事務運作

早就想寫了，一直忘了，其實很簡單

1. 就三條命令

   start transaction
   commit
   rollback

2. 現在來解釋下：

   start transaction;
   就是開始事務追蹤的命令
   開始前一定記得寫

   然後

   commit;
   這個的意思是說確認提交，執行這個命令就不能rollback了，相當於執行完畢。

   最後

   rollback;
   這個命令很簡單，復原到start transaction時候的狀態

3. 現在舉例
   mysql> select * from useraccount ;
   +-----------+--------+-------------+
   | AccountID | userID | AccountName |
   +-----------+--------+-------------+
   | 1 | 2 | zhifubao |
   +-----------+--------+-------------+
   1 row in set (0.00 sec)

   mysql> start transaction;
   Query OK, 0 rows affected (0.00 sec)

   mysql> update useraccount set userID = 1;
   Query OK, 1 row affected (0.00 sec)
   Rows matched: 1 Changed: 1 Warnings: 0

   mysql> select * from useraccount;
   +-----------+--------+-------------+
   | AccountID | userID | AccountName |
   +-----------+--------+-------------+
   | 1 | 1 | zhifubao |
   +-----------+--------+-------------+
   1 row in set (0.00 sec)

   mysql> rollback; (這裡假如不想復原就用commit;就可以完成了）
   Query OK, 0 rows affected (0.28 sec)

   mysql> select * from useraccount;
   +-----------+--------+-------------+
   | AccountID | userID | AccountName |
   +-----------+--------+-------------+
   | 1 | 2 | zhifubao |
   +-----------+--------+-------------+
   1 row in set (0.00 sec)