MySQL用户管理、经常使用sql语句、数据库备份

13.4 MySQL用户管理

建立用户并受权

指定登陆IP

[root@1 ~]# mysql -uroot -p
Enter password: 
Welcome to the MySQL monitor.
mysql> grant all on *.* to 'user1'@'127.0.0.1' identified by '123456';
#建立user1用户并授予其全部权限“*.*”（通配符）
#第一个*表示db_name；第二个*表示tb_name
#同时指定其来源IP127.0.0.1（即，只可经过此IP登陆）
#此处能够使用通配符%，表明全部IP（通常不使用）
#设定密码：identified by
mysql> quit
Bye

指定登陆socket

[root@1 ~]# mysql -uroot -p
Enter password: 
Welcome to the MySQL monitor.
mysql> grant all on *.* to 'user2'@'localhost' identified by '123456';
Query OK, 0 rows affected (0.01 sec)
mysql> quit
Bye

用户登陆

使用IP登陆

[root@1 ~]# mysql -uuser1 -p123456 -h127.0.0.1
Welcome to the MySQL monitor.
mysql> quit
Bye

使用socket登陆

[root@1 ~]# mysql -uuser2 -p'123456'
Welcome to the MySQL monitor. 
mysql> exit
Bye

说明： 由于指定登陆主机为localhost，因此该用户默认使用（监听）本地mysql.socket文件，不须要指定IP便可登陆。

对具体权限进行受权

[root@1 ~]# mysql -uroot -p'123456'
Welcome to the MySQL monitor.
mysql> create database db1;
Query OK, 1 row affected (0.04 sec)
mysql> grant SELECT,UPDATE,INSERT on db1.* to 'user2'@'192.168.8.132' identified by '123456';
#建立user2用户，并授予其针对db1库SELECT,UPDATE,INSERT权限

mysql> grant all on db1.* to 'user'@'%' identified by '123456';
#建立user3，并针对全部IP授予其db1库全部权限

权限相关命令

[root@1 ~]# mysql -uroot -p'123456'
Welcome to the MySQL monitor.
mysql> show grants;
#查看当前用户的权限

mysql> show grants for user2@192.168.8.132;
#查看指定用户的权限

更改权限

[root@1 ~]# mysql -uroot -p'123456'
Welcome to the MySQL monitor.
mysql> GRANT USAGE ON *.* TO 'user2'@'127.0.0.1' IDENTIFIED BY PASSWORD '*6BB4837EB743291105EE4568DDA7DC67ED2CA2AD9';
Query OK, 0 rows affected (0.03 sec)

mysql> GRANT SELECT, INSERT, UPDATE ON `db1`.* TO 'user2'@'127.0.0.1';
Query OK, 0 rows affected (0.00 sec)
mysql> show grants for user2@127.0.0.1;
+--------------------------------------------------------------------------------------------------------------+
| Grants for user2@127.0.0.1                                                                                   |
+--------------------------------------------------------------------------------------------------------------+
| GRANT USAGE ON *.* TO 'user2'@'127.0.0.1' IDENTIFIED BY PASSWORD '*6BB4837EB74329105EE4568DDA7DC67ED2CA2AD9' |
| GRANT SELECT, INSERT, UPDATE ON `db1`.* TO 'user2'@'127.0.0.1'                                               |
+--------------------------------------------------------------------------------------------------------------+
2 rows in set (0.00 sec)

mysql> quit
Bye

注： 更改用户权限时，权限行的内容都要更改。

13.5 经常使用sql语句

[root@1 ~]# mysql -uroot -p'123456';
Welcome to the MySQL monitor.
mysql> use db1;
Database changed
#选择库

mysql> select count(*) from mysql.user;
+----------+
| count(*) |
+----------+
|       12 |
+----------+
1 row in set (0.04 sec)
#查看指定库的内容的行数

mysql> select * from mysql.db\G;
#查看库的全部内容

mysql> select db,user from mysql.db;
#查看库指定内容

mysql> select * from mysql.db where host like '192.168.%'\G;
#查看某些IP对应的库内容，like表示匹配

mysql> create table t1(`id` int(4),`name` char(40));
Query OK, 0 rows affected (0.39 sec)
#在db1库下建立表t1

mysql> select * from db1.t1;
Empty set (0.03 sec)
#查看表中信息：空表

mysql> insert into db1.t1 values(1,'abc');
Query OK, 1 row affected (0.09 sec)
#向表中插入内容
mysql> select * from db1.t1;
+------+------+
| id   | name |
+------+------+
|    1 | abc  |
+------+------+
1 row in set (0.00 sec)

mysql> update db1.t1 set name='aaa' where id=1;
Query OK, 1 row affected (0.08 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> select * from db1.t1;
+------+------+
| id   | name |
+------+------+
|    1 | aaa  |
+------+------+
1 row in set (0.00 sec)
#更改表中指定内容

mysql> delete from db1.t1 where id=1;
Query OK, 2 rows affected (0.10 sec)
#删除表中指定内容
mysql> select * from db1.t1;
Empty set (0.00 sec)

mysql> truncate db1.t1;
Query OK, 0 rows affected (0.09 sec)
#清空一个表中内容

mysql> drop table t1;
Query OK, 0 rows affected (0.04 sec)
#删除表
mysql> drop database db1;
Query OK, 0 rows affected (0.13 sec)
#删除库

mysql> use mysql；
mysql> delete from user where User='user1' and Host='127.0.0.1';
Query OK, 1 row affected (0.06 sec)
#删除用户，在删除用户前须要先指定表

13.6 MySQL数据库备份恢复

备份库

备份指定库：
[root@1 ~]# mysqldump -uroot -p123456 mysql > /tmp/mysqlbak.sql

备份全部库：
[root@1 ~]# mysqldump -uroot -p123456 -A > /tmp/mysql_all.sql

恢复库

[root@1 ~]# mysql -uroot -p123456 < /tmp/mysqlbak.sql

备份表

备份指定表：
[root@1 ~]# mysql -uroot -p123456 mysql user > /tmp/user.sql

只备份表结构：
[root@1 ~]# mysqldump -uroot -p123456 -d mysql > /tmp/mysql_tb.sql

恢复表

[root@1 ~]# mysql -uroot -p123456 mysql user < /tmp/user.sql