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, 2016, 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, 2016, 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, 2016, 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 names
You can turn off this feature to get a quicker startup with -ADatabase changed
mysql> 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, 2016, 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.sql
Warning: 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.sql
Warning: Using a password on the command line interface can be insecure.