Mysql 命令行控制事务
1、创建表
CREATE TABLE `t1` (
`a` int(11) NOT NULL,
`b` int(11) DEFAULT NULL,
PRIMARY KEY (`a`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
2、查看mysql系统级别的事务隔离级别：
mysql> SELECT @@global.tx_isolation;
+-----------------------+
| @@global.tx_isolation |
+-----------------------+
| REPEATABLE-READ |
+-----------------------+
1 row in set (0.00 sec)
3、查看mysql会话级别的事务隔离级别：
mysql> SELECT @@tx_isolation;
+-----------------+
| @@tx_isolation |
+-----------------+
| REPEATABLE-READ |
+-----------------+
1 row in set (0.00 sec)
mysql> SELECT @@session.tx_isolation;
+------------------------+
| @@session.tx_isolation |
+------------------------+
| REPEATABLE-READ |
+------------------------+
1 row in set (0.00 sec)
4、设置系统的事务隔离级别：
mysql> set global transaction isolation level read committed;
Query OK, 0 rows affected (0.00 sec)
mysql> SELECT @@global.tx_isolation;
+-----------------------+
| @@global.tx_isolation |
+-----------------------+
| READ-COMMITTED |
+-----------------------+
1 row in set (0.00 sec)
mysql> SELECT @@tx_isolation;
+-----------------+
| @@tx_isolation |
+-----------------+
| REPEATABLE-READ |
+-----------------+
1 row in set (0.00 sec)
5、设置会话的事务隔离级别：
mysql> set session transaction isolation level read committed;
Query OK, 0 rows affected (0.00 sec)
mysql> SELECT @@global.tx_isolation;
+-----------------------+
| @@global.tx_isolation |
+-----------------------+
| READ-COMMITTED |
+-----------------------+
1 row in set (0.00 sec)
mysql> SELECT @@tx_isolation;
+----------------+
| @@tx_isolation |
+----------------+
| READ-COMMITTED |
+----------------+
1 row in set (0.00 sec)
6、mysql默认是自动提交事务的，查看autocommit变量：
mysql> select @@autocommit;
+--------------+
| @@autocommit |
+--------------+
| 1 |
+--------------+
1 row in set (0.01 sec)
7、设置mysql不自动提交事务：
mysql> set autocommit = 0;
Query OK, 0 rows affected (0.00 sec)
mysql> select @@autocommit;
+--------------+
| @@autocommit |
+--------------+
| 0 |
+--------------+
1 row in set (0.01 sec)
8、使用start transaction;或begin;显示的开启一个事务:
mysql> start transaction;
Query OK, 0 rows affected (0.00 sec)
mysql> begin;
Query OK, 0 rows affected (0.00 sec)
mysql> insert into t1 values (51, 3000);
Query OK, 1 row affected (0.00 sec)
mysql> select * from t1;
+----+------+
| a | b |
+----+------+
| 51 | 3000 |
+----+------+
1 row in set (0.00 sec)
mysql> rollback;
Query OK, 0 rows affected (0.04 sec)
mysql> select * from t1;
Empty set (0.00 sec)
mysql> commit;
Query OK, 0 rows affected (0.00 sec)
mysql> select * from t1;
Empty set (0.00 sec)
9、使用rollback回滚事务
mysql> select * from t1;
Empty set (0.00 sec)
mysql> insert into t1 values (51, 3000);
Query OK, 1 row affected (0.00 sec)
mysql> select * from t1;
+----+------+
| a | b |
+----+------+
| 51 | 3000 |
+----+------+
1 row in set (0.00 sec)
mysql> rollback;
Query OK, 0 rows affected (0.03 sec)
mysql> select * from t1;
Empty set (0.00 sec)
10、使用savepoint在事务中创建一个保存点（可以在一个事务中创建多个保存点）
mysql> begin;
Query OK, 0 rows affected (0.00 sec)
mysql> insert into t1 values (51, 3000);
Query OK, 1 row affected (0.00 sec)
mysql> select * from t1;
+----+------+
| a | b |
+----+------+
| 51 | 3000 |
+----+------+
1 row in set (0.00 sec)
mysql> savepoint tx1;
Query OK, 0 rows affected (0.00 sec)
mysql> insert into t1 values (52, 3000);
Query OK, 1 row affected (0.00 sec)
mysql> select * from t1;
+----+------+
| a | b |
+----+------+
| 51 | 3000 |
| 52 | 3000 |
+----+------+
2 rows in set (0.00 sec)
mysql> rollback to tx1;
Query OK, 0 rows affected (0.00 sec)
mysql> select * from t1;
+----+------+
| a | b |
+----+------+
| 51 | 3000 |
+----+------+
1 row in set (0.00 sec)
mysql> commit;
Query OK, 0 rows affected (0.04 sec)