mysql用户管理
1.创建一个普通用户并授权
[root@gary-tao ~]# mysql -uroot -p'szyino-123'Warning: Using a password on the command line interface can be insecure.Welcome to the MySQL monitor. Commands end with ; or \g.Your MySQL connection id is 24 Server version: 5.6.35 MySQL Community Server (GPL) Copyright (c) 2000, , 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> grant all on *.* to 'user1'@'127.0.0.1' identified by 'szyino-123'; //创建一个普通用户并授权 Query OK, 0 rows affected (0.00 sec)
用法解释说明：
grant：授权；all:表示所有的权限（如读、写、查询、删除等操作）；.：前者表示所有的数据库,后者表示所有的表；identified by：后面跟密码，用单引号括起来；'user1'@'127.0.0.1':指定IP才允许这个用户登录，这个IP可以使用%代替，表示允许所有主机使用这个用户登录;2.测试登录
[root@gary-tao ~]# mysql -uuser1 -pszyino-123 //由于指定IP，报错不能登录Warning: Using a password on the command line interface can be insecure.ERROR 1045 (28000): Access denied for user 'user1'@'localhost' (using password: YES) [root@gary-tao ~]# mysql -uuser1 -pszyino-123 -h127.0.0.1 //加-h指定IP登录，正常 Warning: Using a password on the command line interface can be insecure. Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 26 Server version: 5.6.35 MySQL Community Server (GPL) Copyright (c) 2000, , 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> mysql> grant all on *.* to 'user1'@'localhost' identified by 'szyino-123'; //授权localhost，所以该用户默认使用（监听）本地mysql.socket文件，不需要指定IP即可登录 Query OK, 0 rows affected (0.00 sec) mysql> ^DBye [root@gary-tao ~]# mysql -uuser1 -pszyino-123 //正常登录 Warning: Using a password on the command line interface can be insecure. Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 28 Server version: 5.6.35 MySQL Community Server (GPL) Copyright (c) 2000, , 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>
3.查看所有授权
mysql> show grants;+----------------------------------------------------------------------------------------------------------------------------------------+| Grants for root@localhost|+----------------------------------------------------------------------------------------------------------------------------------------+| GRANT ALL PRIVILEGES ON *.* TO 'root'@'localhost' IDENTIFIED BY PASSWORD '*B1E761CAD4A61F6FD6B02848B5973BC05DE1C315' WITH GRANT OPTION || GRANT PROXY ON ''@'' TO 'root'@'localhost' WITH GRANT OPTION | +----------------------------------------------------------------------------------------------------------------------------------------+ 2 rows in set (0.00 sec)
4.指定用户查看授权
mysql> show grants for user1@'127.0.0.1';+-----------------------------------------------------------------------------------------------------------------------+| Grants for user1@127.0.0.1 |+-----------------------------------------------------------------------------------------------------------------------+| GRANT ALL PRIVILEGES ON *.* TO 'user1'@'127.0.0.1' IDENTIFIED BY PASSWORD '*B1E761CAD4A61F6FD6B02848B5973BC05DE1C315' | +-----------------------------------------------------------------------------------------------------------------------+ 1 row in set (0.00 sec)
注意：假设你想给同个用户授权增加一台电脑IP授权访问，你就可以直接拷贝查询用户授权文件，复制先执行一条命令再执行第二条，执行的时候把IP更改掉,这样就可以使用同个用户密码在另外一台电脑上登录。
常用sql语句
1.最常见的查询语句
第一种形式:
mysql> use db1;Reading table information for completion of table and column namesYou can turn off this feature to get a quicker startup with -ADatabase changedmysql> select count(*) from mysql.user; +----------+ | count(*) | +----------+ | 8 | +----------+ 1 row in set (0.00 sec) //注释：mysql.user表示mysql的user表，count(*)表示表中共有多少行。
第二种形式:
mysql> select * from mysql.db;//它表示查询mysql库的db表中的所有数据mysql> select db from mysql.db; +---------+ | db | +---------+ | test | | test\_% | +---------+ 2 rows in set (0.00 sec) //查询db表里的db单个字段 mysql> select db,user from mysql.db; +---------+------+ | db | user | +---------+------+ | test | | | test\_% | | +---------+------+ 2 rows in set (0.00 sec) //查看db表里的db，user多个字段 mysql> select * from mysql.db where host like '192.168.%'\G; //查询db表里关于192.168.段的ip信息
2.插入一行
mysql> desc db1.t1;+-------+----------+------+-----+---------+-------+| Field | Type| Null | Key | Default | Extra |+-------+----------+------+-----+---------+-------+| id | int(4) | YES || NULL | || name | char(40) | YES || NULL | |+-------+----------+------+-----+---------+-------+2 rows in set (0.00 sec) mysql> select * from db1.t1; Empty set (0.00 sec) mysql> insert into db1.t1 values (1, 'abc'); //插入一行数据 Query OK, 1 row affected (0.01 sec) mysql> select * from db1.t1; +------+------+ | id | name | +------+------+ | 1 | abc | +------+------+ 1 row in set (0.00 sec) mysql> insert into db1.t1 values (1, '234'); Query OK, 1 row affected (0.00 sec) mysql> select * from db1.t1; +------+------+ | id | name | +------+------+ | 1 | abc | | 1 | 234 | +------+------+ 2 rows in set (0.00 sec)
3.更改表的一行。
mysql> update db1.t1 set name='aaa' where id=1;Query OK, 2 rows affected (0.01 sec) Rows matched: 2 Changed: 2 Warnings: 0 mysql> select * from db1.t1; +------+------+ | id | name | +------+------+ | 1 | aaa | | 1 | aaa | +------+------+ 2 rows in set (0.00 sec)
4.清空某个表的数据
mysql> truncate table db1.t1; //清空表Query OK, 0 rows affected (0.03 sec)mysql> select * from db1.t1;Empty set (0.00 sec) mysql> desc db1.t1; +-------+----------+------+-----+---------+-------+ | Field | Type | Null | Key | Default | Extra | +-------+----------+------+-----+---------+-------+ | id | int(4) | YES | | NULL | | | name | char(40) | YES | | NULL | | +-------+----------+------+-----+---------+-------+ 2 rows in set (0.00 sec)
5.删除表
mysql> drop table db1.t1;Query OK, 0 rows affected (0.01 sec)mysql> select * from db1.t1;ERROR 1146 (42S02): Table 'db1.t1' doesn't exist
6.删除数据库
mysql> drop database db1;Query OK, 0 rows affected (0.00 sec)
mysql数据库备份恢复
1.备份恢复库
[root@gary-tao ~]# mysqldump -uroot -pszyino-123 mysql > /tmp/mysql.sql //备份库Warning: Using a password on the command line interface can be insecure.[root@gary-tao ~]# mysql -uroot -pszyino-123 -e "create database mysql2" //创建一个新的库Warning: Using a password on the command line interface can be insecure.[root@gary-tao ~]# mysql -uroot -pszyino-123 mysql2 < /tmp/mysql.sql //恢复一个库 Warning: Using a password on the command line interface can be insecure. [root@gary-tao ~]# mysql -uroot -pszyino-123 mysql2 Warning: Using a password on the command line interface can be insecure. Reading table information for completion of table and column names You can turn off this feature to get a quicker startup with -A Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 38 Server version: 5.6.35 MySQL Community Server (GPL) Copyright (c) 2000, , 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> select database(); +------------+ | database() | +------------+ | mysql2 | +------------+ 1 row in set (0.00 sec)
2.备份恢复表
[root@gary-tao ~]# mysqldump -uroot -pszyino-123 mysql user > /tmp/user.sql //备份表Warning: Using a password on the command line interface can be insecure.[root@gary-tao ~]# mysql -uroot -pszyino-123 mysql2 < /tmp/user.sql //恢复表Warning: Using a password on the command line interface can be insecure.
3.备份所有库
[root@gary-tao ~]# mysqldump -uroot -pszyino-123 -A > /tmp/mysql_all.sqlWarning: Using a password on the command line interface can be insecure.[root@gary-tao ~]# less /tmp/mysql_all.sql
4.只备份表结构
[root@gary-tao ~]# mysqldump -uroot -pszyino-123 -d mysql > /tmp/mysql.sqlWarning: Using a password on the command line interface can be insecure.
