整理是最好的记忆
运维经常用到的sql语句，长期更新~~~~~
1、查看有哪些用户
mysql> select user,host from mysql.user;
+------------+-----------+
| user | host |
+------------+-----------+
| root | 127.0.0.1 |
| mysql_data | localhost |
| root | localhost |
| zabbix | localhost |
+------------+-----------+
2、查看mysql版本 位数
mysql> select version();
+-----------+
| version() |
+-----------+
| 5.6.32 |
+-----------+
mysql> show variables like ‘%version_%‘;
+-------------------------+------------------------------+
| Variable_name | Value |
+-------------------------+------------------------------+
| slave_type_conversions | |
| version_comment | MySQL Community Server (GPL) |
| version_compile_machine | i686 |
| version_compile_os | Linux |
+-------------------------+------------------------------+
4 rows in set (0.00 sec)
3、查看当前登录用户
mysql> select user();
+----------------+
| user() |
+----------------+
| root@localhost |
+----------------+
4.查看二进制日志是否开启
mysql> show variables like "log_bin";
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| log_bin | OFF |
+---------------+-------+
5.查看默认存储引擎
mysql> show variables like ‘storage_engine%‘;
+----------------+--------+
| Variable_name | Value |
+----------------+--------+
| storage_engine | MyISAM |
+----------------+--------+
6.数据库
mysql> create database zabbix;
Query OK, 1 row affected (0.12 sec)
mysql> create database zabbix character set utf8; --->创建数据库并设置字符集
Query OK, 1 row affected (0.00 sec)
mysql> show databases; ---> 显示数据库
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| testdb |
| zabbix |
+--------------------+
mysql> use zabbix; ---> 选择数据库
Database changed
mysql> show create database zabbix; ---> 查看建库的完整语句
+----------+-----------------------------------------------------------------+
| Database | Create Database |
+----------+-----------------------------------------------------------------+
| zabbix | CREATE DATABASE `zabbix` /*!40100 DEFAULT CHARACTER SET utf8 */ |
+----------+-----------------------------------------------------------------+
mysql> drop database zabbix; --->删除数据库
7.数据表
mysql> create table zabbix(user_id int primary key,user_name varchar(20),user_gender varchar(20)); --->创建一个表zabbix
Query OK, 0 rows affected (0.43 sec)
mysql> show tables; --->显示所有的表
+------------------+
| Tables_in_zabbix |
+------------------+
| zabbix |
+------------------+
mysql> desc zabbix; --->显示表结构
+-------------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------------+-------------+------+-----+---------+-------+
| user_id | int(11) | NO | PRI | NULL | |
| user_name | varchar(20) | YES | | NULL | |
| user_gender | varchar(20) | YES | | NULL | |
+-------------+-------------+------+-----+---------+-------+
Insert into TableName (列1,列2.... 列n） Values (值1,值2,....值n)
如果没有声明列明,则默认插入所有列.因此,值应该与全部列,按顺序一一对应.
mysql> insert into zabbix values(‘1‘,‘xiaoming‘,‘boy‘); --->向表中插入一列数据
mysql> select * from zabbix;
+---------+-----------+-------------+
| user_id | user_name | user_gender |
+---------+-----------+-------------+
| 1 | xiaoming | boy |
| 2 | laowang | boy |
| 3 | marong | girl |
+---------+-----------+-------------+
Update 表名 Set 列1 = 新值 1,列2 = 新值2,列n = 新值n..... Where **
mysql> update zabbix set user_gender=‘girl‘ where user_id="1"; --->修改数据
mysql> select * from zabbix;
+---------+-----------+-------------+
| user_id | user_name | user_gender |
+---------+-----------+-------------+
| 1 | xiaoming | girl |
mysql> truncate zabbix; --->清空表数据
mysql> select * from zabbix;
Empty set (0.00 sec)
mysql> drop table zabbix; --->删除表
Query OK, 0 rows affected (0.05 sec)
增加主键
alter table tbName add primary key(主键所在列名);
例:alter table goods add primary key(id)
该例是把主键建立在id列上
修改表之删除主键
alter table tbName drop primary key;
修改表之增加索引
alter table tbName add [unique|fulltext] index 索引名(列名);
修改表之删除索引
alter table tbName drop index 索引名;
8.备份数据库
mysqldump -u root -p zabbix>/zabbix.sql ----备份数据库zabbix
mysql -uroot -p zdj</mysql/zdj.sql ----恢复数据库
mysqldump -uroot -p --all-databases >all2.sql 备份所有的库
mysql -uroot -p <all2.sql 恢复所有的库
9.用户授权管理
格式：grant 权限 on 数据库名.表名 to 用户@登录主机 identified by "用户密码";
@ 后面是访问mysql的客户端IP地址（或是 主机名） % 代表任意的客户端，如果填写 localhost 为本地访问（那此用户就不能远程访问该mysql数据库了）。
mysql> grant all privileges on *.* to zabbix@‘%‘ identified by "123456";
mysql> show grants for zabbix\G; ---- 》查看创建用户的权限
*************************** 1. row ***************************
Grants for zabbix@%: GRANT ALL PRIVILEGES ON *.* TO ‘zabbix‘@‘%‘ IDENTIFIED BY PASSWORD ‘*6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9‘
mysql> delete from mysql.user where user=‘zabbix‘ and host=‘%‘;---> 删除用户
10.查看库大小：
MariaDB [information_schema]> SELECT SUM(DATA_LENGTH)+SUM(INDEX_LENGTH) FROM information_schema.tables WHERE TABLE_SCHEMA=‘drcom‘;
+------------------------------------+
| SUM(DATA_LENGTH)+SUM(INDEX_LENGTH) |
+------------------------------------+
| 26051771392 |
+------------------------------------+
1 row in set (0.42 sec)
结果是以字节为单位，除1024为K，除1048576为M。
11.查看表总数：
SELECT count(TABLE_NAME) FROM information_schema.TABLES WHERE TABLE_SCHEMA=‘drcomweixin‘;-->
12.查看表大小：
SELECT TABLE_NAME,DATA_LENGTH+INDEX_LENGTH,TABLE_ROWS FROM information_schema.tables WHERE TABLE_SCHEMA=‘库‘ AND TABLE_NAME=‘表名‘;
13.show processlist;
http://renxiangzyq.iteye.com/blog/835397
mysql线程数
[root@vps /]# mysqladmin processlist -uroot -p |wc -l
Enter password:
24
14.查看最大连接数
[root@vps /]# mysql -uroot -p -e "show variables like ‘%max_connections%‘;"
Enter password:
+-----------------------+-------+
| Variable_name | Value |
+-----------------------+-------+
| extra_max_connections | 1 |
| max_connections | 1000 |
+-----------------------+-------+
15.查看当前连接数
[root@vps /]# mysql -uroot -p -e "show status like ‘Threads%‘;"
Enter password:
+-------------------+-------+
| Variable_name | Value |
+-------------------+-------+
| Threads_cached | 5 |
| Threads_connected | 16 |
| Threads_created | 1697 |
| Threads_running | 3 |
+-------------------+-------+
16.mysql查看状态
mysql> show status;
[root@vps ~]# mysqladmin -uroot -p***** status
Warning: Using a password on the command line interface can be insecure.
Uptime: 8135940 Threads: 17 Questions: 117931987 Slow queries: 0 Opens: 215 Flush tables: 1 Open tables: 208 Queries per second avg: 14.495
~~~~~未完待续
本文出自 “拔电源的运维空间” 博客，请务必保留此出处http://zhangdj.blog.51cto.com/9210512/1878480
原文地址：http://zhangdj.blog.51cto.com/9210512/1878480
