MySQL Study之--MySQL关闭自动commit（autocommit）

MySQL Study之--MySQL关闭自动commit（autocommit）

     对于mysql来讲，在事务处理时，默认是在动提交的（autocommit），以下方法可以自动关闭autocommit；

案例分析：

1、在mysql登录环境下修改

[root@mysql2 soft]# mysql -u root -p

Enter password: 

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is 4

Server version: 5.6.25-73.1 Percona Server (GPL), Release 73.1, Revision 07b797f

Copyright (c) 2009-2015 Percona LLC and/or its affiliates

Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its

affiliates. Other names may be trademarks of their respective

owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> show databases;

+--------------------+

| Database           |

+--------------------+

| information_schema |

| mysql              |

| performance_schema |

| test               |

+--------------------+

4 rows in set (0.02 sec)

mysql> select version();

+-------------+

| version()   |

+-------------+

| 5.6.25-73.1 |

+-------------+

1 row in set (0.00 sec)

mysql> show variables like '%autocommit%';

+---------------+-------+

| Variable_name | Value |

+---------------+-------+

| autocommit    | ON    |                ；；默认autocommit是开启的

+---------------+-------+

1 row in set (0.03 sec)

在当前session关闭autocommit：

mysql> set @@session.autocommit=0;

Query OK, 0 rows affected (0.00 sec)

mysql> show variables like '%autocommit%';

+---------------+-------+

| Variable_name | Value |

+---------------+-------+

| autocommit    | OFF   |

+---------------+-------+

1 row in set (0.00 sec)

在global级别关闭autocommit：

mysql> set @@global.autocommit=0;

Query OK, 0 rows affected (0.01 sec)

创建普通用户：

mysql> create user tom identified by 'tom';

Query OK, 0 rows affected (0.00 sec)

mysql> grant all on prod.* to 'tom'@'localhost' identified by 'tom';

Query OK, 0 rows affected (0.00 sec)

mysql> flush privileges;

Query OK, 0 rows affected (0.00 sec)

普通用户登录：

[root@mysql2 ~]# mysql -u tom -p

Enter password: 

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is 6

Server version: 5.6.25-73.1 Percona Server (GPL), Release 73.1, Revision 07b797f

Copyright (c) 2009-2015 Percona LLC and/or its affiliates

Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its

affiliates. Other names may be trademarks of their respective

owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> use mysql;

ERROR 1044 (42000): Access denied for user 'tom'@'localhost' to database 'mysql'

mysql> use  prod;

Database changed

mysql> show tables;

Empty set (0.00 sec)

mysql> show variables like '%commit%';

+-------------------------------------------+-------+

| Variable_name                             | Value |

+-------------------------------------------+-------+

| autocommit                                | OFF   |

| binlog_order_commits                      | ON    |

| innodb_api_bk_commit_interval             | 5     |

| innodb_commit_concurrency                 | 0     |

| innodb_flush_log_at_trx_commit            | 1     |

| innodb_use_global_flush_log_at_trx_commit | ON    |

+-------------------------------------------+-------+

6 rows in set (0.00 sec)

创建测试表：

mysql> create table t1(id int,name varchar(10));

Query OK, 0 rows affected (0.15 sec)

mysql> insert into t1 values (10,'tom');

Query OK, 1 row affected (0.00 sec)

mysql> select * from t1;

+------+------+

| id   | name |

+------+------+

|   10 | tom

 |

+------+------+

1 row in set (0.00 sec)

事务回滚：

mysql> rollback;

Query OK, 0 rows affected (0.02 sec)

mysql> select * from t1;

Empty set (0.00 sec)

2、在mysql service重启后

mysql server 重启后：

[root@mysql2 ~]# service mysql stop

Shutting down MySQL (Percona Server)....[  OK  ]

[root@mysql2 ~]# service mysql start

Starting MySQL (Percona Server).....[  OK  ]

[root@mysql2 ~]# mysql -u root -p

Enter password: 

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is 1

Server version: 5.6.25-73.1 Percona Server (GPL), Release 73.1, Revision 07b797f

Copyright (c) 2009-2015 Percona LLC and/or its affiliates

Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its

affiliates. Other names may be trademarks of their respective

owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> show variables like '%commit%';

+-------------------------------------------+-------+

| Variable_name                             | Value |

+-------------------------------------------+-------+

| autocommit                                | ON    |             ；；autocommit仍然是开启状态

+-------------------------------------------+-------+

6 rows in set (0.01 sec)

编辑/etc/my.cnf文件：

[root@mysql2 ~]# vi /etc/my.cnf

[mysqld]

datadir=/var/lib/mysql

socket=/var/lib/mysql/mysql.sock

user=mysql

# Disabling symbolic-links is recommended to prevent assorted security risks

symbolic-links=0

init_connect='set autocommit=0'                                    ；；用户登录时，关闭autocommit

[mysqld_safe]

log-error=/var/log/mysqld.log

pid-file=/var/run/mysqld/mysqld.pid

explicit_defaults_for_timestamp=true

innodb_buffer_pool_size = 128M

join_buffer_size = 128M

sort_buffer_size = 2M

read_rnd_buffer_size = 2M

用户登录查看：

[root@mysql2 ~]# mysql -u root -p

Enter password: 

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is 1

Server version: 5.6.25-73.1 Percona Server (GPL), Release 73.1, Revision 07b797f

Copyright (c) 2009-2015 Percona LLC and/or its affiliates

Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its

affiliates. Other names may be trademarks of their respective

owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> show variables like '%commit%';

+-------------------------------------------+-------+

| Variable_name                             | Value |

+-------------------------------------------+-------+

| autocommit                                | ON    |                ；；root用户不受影响（为安全起见）

mysql> system mysql -u tom -p

Enter password: 

Welcome to the MySQL monitor.  Commands end with ; or \g.

Your MySQL connection id is 2

Server version: 5.6.25-73.1 Percona Server (GPL), Release 73.1, Revision 07b797f

Copyright (c) 2009-2015 Percona LLC and/or its affiliates

Copyright (c) 2000, 2015, Oracle and/or its affiliates. All rights reserved.

Oracle is a registered trademark of Oracle Corporation and/or its

affiliates. Other names may be trademarks of their respective

owners.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

mysql> show variables like '%commit%';

+-------------------------------------------+-------+

| Variable_name                             | Value |

+-------------------------------------------+-------+

| autocommit                                | OFF   |                ；；普通用户，autocommit已被关闭

+-------------------------------------------+-------+

©著作权归作者所有：来自51CTO博客作者客居天涯的原创作品，如需转载，请注明出处，否则将追究法律责任

MySQL数据库技术