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MySQL用户管理、常用SQL语句、MySQL数据库备份恢复
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 -h227.0.0.1 //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:
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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 -A
Database 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.网站栏目：MySQL用户管理、常用SQL语句、MySQL数据库备份恢复
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