引言

项目中使用Mysql经常会遇到修改编码格式、导入sql、导出sql、windows授权、查看删除死锁进程等操作。
特总结如下：

1、Mysql批量导入sql

（1）选择数据库 
mysql>use abc; 
（2）设置数据库编码 
mysql>set names utf8; 
（3）导入数据（注意sql文件的路径） 
mysql>source /home/abc/abc.sql;

2、Mysql导出为sql（导出数据和表结构）

mysqldump -u用户名 -p 数据库名 > 数据库名.sql

#/usr/local/mysql/bin/mysqldump -uroot -p abc > abc.sql

敲回车后会提示输入密码

或者通过navicat工具导出。

3、导出结果数据

select * from ly_info where enckeyword = "0"  into outfile '/tmp/ly_insert.txt';

将结果转为sql语句，参考：
http://blog.csdn.net/laoyang360/article/details/53236018

4、Mysql ut8格式修改，目的：防止出现乱码。

最简单的完美修改方法，修改mysql的my.cnf文件中的字符集键值（注意配置的字段细节）：

1）在[client]字段里加入default-character-set=utf8，
如下：

[client]
port = 3306
socket = /var/lib/mysql/mysql.sock
default-character-set=utf8

2）在[mysqld]字段里加入character-set-server=utf8，
如下：

[mysqld]
port = 3306
socket = /var/lib/mysql/mysql.sock
character-set-server=utf8

3）在[mysql]字段里加入default-character-set=utf8，
如下：

[mysql]
no-auto-rehash
default-character-set=utf8

验证方式如下：
使用SHOW VARIABLES LIKE ‘character%’;查看，发现数据库编码全已改成utf8。

+--------------------------+----------------------------+
| Variable_name | Value |
+--------------------------+----------------------------+
| character_set_client | utf8 |
| character_set_connection | utf8 |
| character_set_database | utf8 |
| character_set_filesystem | binary |
| character_set_results | utf8 |
| character_set_server | utf8 |
| character_set_system | utf8 |
| character_sets_dir | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+

4）如果上面的都修改了还乱码，那剩下问题就一定在connection连接层上。
解决方法是在发送查询前执行一下下面这句（直接写在SQL文件的最前面）：
SET NAMES ‘utf8’;

它相当于下面的三句指令：

SET character_set_client = utf8;
SET character_set_results = utf8;
SET character_set_connection = utf8;

5、mysql远程windows授权命令

错误：Access denied for user ‘root@IP’ (using password: YES)

mysql> GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY 'password@!' WITH GRANT OPTION;

6、查询、更新操作

SELECT count(1) AS num, 'qd_last' AS info FROM `qd_info` WHERE enckeyword = "0";
update ya_info t1 , ls_info t2 set t1.id_new = t2.id_new  where t1._id = t2._id;
alter table qd_info add `word` varchar(256) NOT NULL DEFAULT '0', add `update_time` timestamp NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP;

7、查看死锁表死锁

show processlist ;
mysql> show processlist;
+--------+------+--------------------+------+---------+------+----------+------------------------------------------------------------------------------------------------------+
| Id | User | Host | db | Command | Time | State | Info |
+--------+------+--------------------+------+---------+------+----------+------------------------------------------------------------------------------------------------------+
| 219733 | root | 10.200.1.137:38012 | test | Sleep | 1659 | | NULL |
| 219749 | root | 10.200.1.137:38071 | test | Query | 85 | Locked | SELECT count(1) AS num, 't_last' AS info FROM `com_info` WHERE enckeyword = "0"

解决方法： 关闭用不到的连接

mysql> kill 219733 ;

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作者：铭毅天下
转载请标明出处，原文地址：
http://blog.csdn.net/laoyang360/article/details/53523554