Mysql更换MyISAM存储引擎为Innodb操作记录的示例代码分享

一般情况下，mysql会默认提供多种存储引擎,可以通过下面的查看:

1）查看mysql是否安装了innodb插件。

通过下面的命令结果可知，已经安装了innodb插件。

mysql> show plugins; 
+------------+--------+----------------+---------+---------+ 
| Name | Status | Type | Library | License | 
+------------+--------+----------------+---------+---------+ 
| binlog | ACTIVE | STORAGE ENGINE | NULL | GPL | 
| partition | ACTIVE | STORAGE ENGINE | NULL | GPL | 
| CSV | ACTIVE | STORAGE ENGINE | NULL | GPL | 
| MEMORY | ACTIVE | STORAGE ENGINE | NULL | GPL | 
| InnoDB | ACTIVE | STORAGE ENGINE | NULL | GPL | 
| MyISAM | ACTIVE | STORAGE ENGINE | NULL | GPL | 
| MRG_MYISAM | ACTIVE | STORAGE ENGINE | NULL | GPL | 
+------------+--------+----------------+---------+---------+ 
7 rows in set (0.00 sec)

----------------------------------------------------------------------
如果发现没有安装innodb插件,可以执行下面语句进行安装：

mysql> install plugin innodb soname 'ha_innodb.so';

----------------------------------------------------------------------

2）查看mysql现在已提供什么存储引擎:

mysql> show engines; 
+------------+---------+------------------------------------------------------------+--------------+------+------------+ 
| Engine | Support | Comment | Transactions | XA | Savepoints | 
+------------+---------+------------------------------------------------------------+--------------+------+------------+ 
| MRG_MYISAM | YES | Collection of identical MyISAM tables | NO | NO | NO | 
| CSV | YES | CSV storage engine | NO | NO | NO | 
| MyISAM | DEFAULT | Default engine as of MySQL 3.23 with great performance | NO | NO | NO | 
| InnoDB | YES | Supports transactions, row-level locking, and foreign keys | YES | YES | YES | 
| MEMORY | YES | Hash based, stored in memory, useful for temporary tables | NO | NO | NO | 
+------------+---------+------------------------------------------------------------+--------------+------+------------+ 
5 rows in set (0.00 sec)

3）查看mysql当前默认的存储引擎:

mysql> show variables like '%storage_engine%'; 
+----------------+--------+ 
| Variable_name | Value | 
+----------------+--------+ 
| storage_engine | MyISAM | 
+----------------+--------+ 
1 row in set (0.00 sec)

4）看某个表用了什么引擎(在显示结果里参数engine后面的就表示该表当前用的存储引擎):

mysql> show create table 表名;

mysql> show create table wx_share_log; 
+--------------+----------------------------------------------------------------------------------------------------------------------------------+ 
| Table | Create Table | 
+--------------+------------------------------------------------------------------------------------------------------------------------------------+ 
| wx_share_log | CREATE TABLE `wx_share_log` ( 
 `id` int(11) NOT NULL AUTO_INCREMENT COMMENT '微信分享日志自增ID', 
 `reference_id` int(11) NOT NULL COMMENT '推荐的经纪人id', 
 `create_time` datetime NOT NULL COMMENT '创建时间', 
 PRIMARY KEY (`id`) 
) ENGINE=MyISAM AUTO_INCREMENT=13 DEFAULT CHARSET=utf8 | 
+--------------+--------------------------------------------------------------------------------------------------------------------------------------+ 
1 row in set (0.00 sec)

5）如何将MyISAM库导成INNODB引擎格式的:

在备份出的xxx.sql文件中把ENGINE=MyISAM全换成ENGINE=INNODB
再次导入就可以了。

6）转换表的命令:

mysql> alter table 表名 engine=innodb;

有上面可以查到看，本机mysql使用的存储引擎是默认的MyISAN，由于业务需要，先要将其存储引擎改为Innodb。

操作记录如下：

1）以安全模式关闭mysql

[root@dev mysql5.1.57]# mysqladmin -uroot -p shutdown
Enter password: 
[root@dev mysql5.1.57]# ps -ef|grep mysql

2）备份my.cnf

[root@dev mysql5.1.57]# cp my.cnf my.cnf.old

3）修改my.cnf配置文件

[root@dev mysql5.1.57]# vim my.cnf
.....
[mysqld] 
 //在这个配置区域添加下面一行，指定存储引擎为innodb
default-storage-engine = InnoDB

4）删除/mysql/data目录下的ib_logfile0，ib_logfile1。删除或剪切到别处都行。

[root@dev var]# mv ib_logfile0 ib_logfile1 /tmp/back/

5）启动mysql，登陆mysql验证存储引擎是否已切换

[root@dev var]# /Data/app/mysql5.1.57/bin/mysqld_safe --defaults-file=/Data/app/mysql5.1.57/my.cnf &

mysql> show variables like '%storage_engine%'; 
+----------------+--------+ 
| Variable_name | Value | 
+----------------+--------+ 
| storage_engine | InnoDB | 
+----------------+--------+ 
1 row in set (0.00 sec)