2018-05-08 Linux学习

Posted 2020-11-03

13.4 mysql用户管理

MySQL 创建用户以及授权

grant all on *.* to ‘user1‘ identified by ‘passwd‘;
grant SELECT,UPDATE,INSERT on db1.* to ‘user2‘@‘192.168.133.1‘ identified by ‘passwd‘;
grant all on db1.* to ‘user3‘@‘%‘ identified by ‘passwd‘;
show grants;
show grants for [email protected];

grant 不会记录到命令历史记录里，不安全

操作过程

mysql> grant all on *.* to ‘user1‘@‘127.0.0.1‘ identified by ‘123456a‘;
Query OK, 0 rows affected (0.00 sec)

[[email protected] ~]# mysql -uuser1 -p123456a -h127.0.0.1
Warning: Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.

mysql> grant all on *.* to ‘user1‘@‘localhost‘ identified by ‘123456a‘;
Query OK, 0 rows affected (0.00 sec)

[[email protected] ~]# mysql -uuser1 -p123456a
Warning: Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.

mysql> grant SELECT,UPDATE,INSERT on db1.* to ‘user2‘@‘192.168.106.1‘ identified by ‘passwd‘;
Query OK, 0 rows affected (0.00 sec)

mysql> grant all on db1.* to ‘user3‘@‘%‘ identified by ‘passwd‘;
Query OK, 0 rows affected (0.01 sec)

mysql> show grants for [email protected]‘192.168.106.1‘;
+------------------------------------------------------------------------------------------------------------------+
| Grants for [email protected]                                                                                   |
+------------------------------------------------------------------------------------------------------------------+
| GRANT USAGE ON *.* TO ‘user2‘@‘192.168.106.1‘ IDENTIFIED BY PASSWORD ‘*59C70DA2F3E3A5BDF46B68F5C8B8F25762BCCEF0‘ |
| GRANT SELECT, INSERT, UPDATE ON `db1`.* TO ‘user2‘@‘192.168.106.1‘                                               |
+------------------------------------------------------------------------------------------------------------------+
2 rows in set (0.01 sec)

同一用户，一样密码，在两个不同IP终端登陆

mysql> GRANT USAGE ON *.* TO ‘user2‘@‘192.168.106.2‘ IDENTIFIED BY PASSWORD ‘*59C70DA2F3E3A5BDF46B68F5C8B8F25762BCCEF0‘;
Query OK, 0 rows affected (0.00 sec)

mysql> show grants for [email protected]‘192.168.106.2‘;

13.5 常用sql语句

select count() from mysql.user;
select from mysql.db;
select db from mysql.db;
select db,user from mysql.db;
select * from mysql.db where host like ‘192.168.%‘;
insert into db1.t1 values (1, ‘abc‘);
update db1.t1 set name=‘aaa‘ where id=1;
truncate table db1.t1;
drop table db1.t1;
drop database db1;

操作过程

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(*) |
+----------+
|       12 |
+----------+
1 row in set (0.00 sec)

mysql> select * from mysql.db;     //耗费资源大，不建议这样操作

mysql> select db from mysql.db;
+---------+
| db      |
+---------+
| db1     |
| test    |
| test\_% |
| db1     |
+---------+
4 rows in set (0.00 sec)

mysql> select db,user from mysql.db;
+---------+-------+
| db      | user  |
+---------+-------+
| db1     | user3 |
| test    |       |
| test\_% |       |
| db1     | user2 |
+---------+-------+
4 rows in set (0.00 sec)

mysql> select * from mysql.db where host like ‘192.168.%‘;

插入数据：没有做限制时，插入数据可以是相同的ID name

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‘);
Query OK, 1 row affected (0.00 sec)

mysql> insert into db1.t1 values (1, ‘123‘);
Query OK, 1 row affected (0.00 sec)

mysql> insert into db1.t1 values (1, ‘123‘);
Query OK, 1 row affected (0.00 sec)

mysql> select * from db1.t1;
+------+------+
| id   | name |
+------+------+
|    1 | abc  |
|    1 | abc  |
|    1 | 123  |
+------+------+
3 rows in set (0.00 sec)

更新表

mysql> update db1.t1 set name=‘aaa‘ where id=1;
Query OK, 3 rows affected (0.01 sec)
Rows matched: 3  Changed: 3  Warnings: 0

mysql> select * from db1.t1;
+------+------+
| id   | name |
+------+------+
|    1 | aaa  |
|    1 | aaa  |
|    1 | aaa  |
+------+------+
3 rows in set (0.00 sec)

mysql> update db1.t1 set id=2 where name=‘aaa‘;
Query OK, 3 rows affected (0.00 sec)
Rows matched: 3  Changed: 3  Warnings: 0

mysql> select * from db1.t1;
+------+------+
| id   | name |
+------+------+
|    2 | aaa  |
|    2 | aaa  |
|    2 | aaa  |
+------+------+
3 rows in set (0.00 sec)

删除

mysql> delete from db1.t1 where id=2;
Query OK, 3 rows affected (0.00 sec)

mysql> select * from db1.t1;
Empty set (0.00 sec)

删除清空表，truncate 清空信息，表结构保留；drop 整个清除

工作中尽量不这样操作

mysql> insert into db1.t1 values (1, ‘123‘);
Query OK, 1 row affected (0.00 sec)

mysql> select * from db1.t1;
+------+------+
| id   | name |
+------+------+
|    1 | 123  |
+------+------+
1 row in set (0.00 sec)

mysql> truncate db1.t1;
Query OK, 0 rows affected (0.01 sec)

mysql> select * from db1.t1;
Empty set (0.00 sec)

mysql> drop table t1;
Query OK, 0 rows affected (0.00 sec)

mysql> select * from db1.t1;
ERROR 1146 (42S02): Table ‘db1.t1‘ doesn‘t exist

mysql> drop database db1;
Query OK, 0 rows affected (0.00 sec)

13.6 MySQL数据库备份恢复

备份库 mysqldump -uroot -p123456 mysql > /tmp/mysql.sql
恢复库 mysql -uroot -p123456 mysql < /tmp/mysql.sql
备份表 mysqldump -uroot -p123456 mysql user > /tmp/user.sql
恢复表 mysql -uroot -p123456 mysql < /tmp/user.sql
备份所有库 mysqldump -uroot -p -A >/tmp/123.sql
只备份表结构 mysqldump -uroot -p123456 -d mysql > /tmp/mysql.sql

操作过程

[[email protected] ~]# mysqldump -uroot -paminglinux mysql> /tmp/mysqlbak.sql
Warning: Using a password on the command line interface can be insecure.

[[email protected] ~]# mysql -uroot -paminglinux -e "create database mysql2"
Warning: Using a password on the command line interface can be insecure.

[[email protected] ~]# mysql -uroot -paminglinux mysql2 < /tmp/mysqlbak.sql 
Warning: Using a password on the command line interface can be insecure.

[[email protected] ~]# mysqldump -uroot -paminglinux mysql user > /tmp/mysqluser.sql
Warning: Using a password on the command line interface can be insecure.

[[email protected] ~]# mysql -uroot -paminglinux mysql2 < /tmp/mysqluser.sql 
Warning: Using a password on the command line interface can be insecure.

[[email protected] ~]# mysqldump -uroot -paminglinux mysql -A > /tmp/mysql-all.sql
Warning: Using a password on the command line interface can be insecure.