1.设置root密码

方法1： 用SET PASSWORD命令

mysql -u root

SET PASSWORD FOR 'root'@'localhost' = PASSWORD('newpass');

方法2：用mysqladmin

mysqladmin -u root password "newpass"

方法3：升级设置

mysql -u root

use mysql;

UPDATE user SET Password = PASSWORD('newpass') WHERE user = 'root';

FLUSH PRIVILEGES;

2.在丢失root密码的时候，可以这样

mysqld_safe --skip-grant-tables&

mysql -u root mysql

UPDATE user SET password=PASSWORD("new password") WHEREuser='root';

FLUSH PRIVILEGES;

3.授权用户查询、插入、更新、删除权限

grant select,insert,update,delete on redmine1.* touser@"%" identified by "user";

4.新增超级权限并允许远程访问

GRANT ALL PRIVILEGES ON *.* TO 'user'@'192.168.1.3' IDENTIFIED BY'mypassword' WITH GRANT OPTION;

FLUSH  PRIVILEGES;

5.切换数据库

use mysql

6.查看所有用户

select user,host from mysql.user;

7.查询、删除匿名用户

select from mysql.user where user='';

delete from mysql.user where user='';

8.查看用户列表

SELECT DISTINCT CONCAT('User: ''',user,'''@''',host,''';') AS queryFROM mysql.user;

9.查看用户权限

show grants for root@'localhost';

10.查看用户具体权限

select * from mysql.user where user='root' \G

11.查看表的权限

use mysql

desc mysql.user;

12.运行中的mysql状态查看

对正在运行的mysql进行监控，其中一个方式就是查看mysql运行状态。

(1)QPS(每秒Query量)

QPS= Questions(or Queries) / seconds

show  global  status like 'Question%';

(2)TPS(每秒事务量)

TPS= (Com_commit + Com_rollback) / seconds

show global status like 'Com_commit';

show global status like 'Com_rollback';

(3)keyBuffer命中率

show  global   status like   'key%';

key_buffer_read_hits= (1-key_reads / key_read_requests) * 100%

key_buffer_write_hits= (1-key_writes / key_write_requests) * 100%

(4)InnoDBBuffer命中率   www.2cto.com

show status like 'innodb_buffer_pool_read%';

innodb_buffer_read_hits= (1 - innodb_buffer_pool_reads / innodb_buffer_pool_read_requests) * 100%

(5)QueryCache命中率

show status like 'Qcache%';

Query_cache_hits= (Qcahce_hits / (Qcache_hits + Qcache_inserts )) * 100%;

(6)TableCache状态量

show global  status like'open%';

比较 open_tables  与 opend_tables 值

(7)ThreadCache命中率

show global status like 'Thread%';

show global status like 'Connections';

Thread_cache_hits= (1 - Threads_created / connections ) * 100%

(8)锁定状态

show global  status like'%lock%';

Table_locks_waited/Table_locks_immediate=0.3%如果这个比值比较大的话，说明表锁造成的阻塞比较严重。

Innodb_row_lock_waitsinnodb行锁，太大可能是间隙锁造成的

(9)查看主、从状态

show master status;

show slave status;

(10)Tmp Table状况(临时表状况)

show status like 'Create_tmp%';

Created_tmp_disk_tables/Created_tmp_tables

比值最好不要超过10%，如果Created_tmp_tables值比较大， 可能是排序句子过多或者是连接句子不够优化

(11)Binlog Cache使用状况

show status like 'Binlog_cache%';

如果Binlog_cache_disk_use值不为0 ，可能需要调大 binlog_cache_size大小

(12)Innodb_log_waits量

show status like 'innodb_log_waits';

Innodb_log_waits值不等于0的话，表明 innodb log  buffer 因为空间不足而等待

13.查看数据状态：

show global status;

14.查看连接数量

show processlist;

15.查看包含内容表

show global status like %查询内容%;

16.查看数据库状态

status;

17.查看版本信息

select version();

18.备份数据库

mysqldump -u root -p test >test.sqlEnter password: ***

19.查看权限

SHOW GRANTS;

HOW GRANTS FOR root@'localhost';

SELECT * FROM mysql.user WHERE USER='root' AND HOST='localhost'\G

20.回收权限

REVOKE EXECUTE ON *.*FROM user@'%';