mysql安全值守数据库常用语句_mysql安全性控制语句

1.用户权限设置

mysql中用户如何定义

用户名@主机域
1

---

有以下几种表示方式：
1. 10.0.0.51
2. 10.0.0.%
3. %
4. 10.0.0.0/255.255.255.0
5. Db01
6. Localhost
7. 127.0.0.1

1
2
3
4
5
6
7
8
9

• 用户创建

create user 321@'%'identified by '123';
1

• 用户删除

drop user username;
username:删除的用户名

1
2
3

---

权限分为

• 全局：可以管理整个MySQL

• 库：可以管理指定的数据库

• 表：可以管理指定数据库的指定表

• 字段：可以管理指定数据库的指定表的指定字段

• 查看用户权限赋予情况

show grants for xinjing@'%'

1
2

• 用户授权

grant  all privileges on stu.* to ‘xinjing’@’%’ identified by ‘123’ with option;//授权给xinjing在stu库中所有表的所有权限并且还拥有给其他用户授权的权利
revoke all privileges on stu.* from 'xinjing'@'%'; //取消授权


1
2
3
4

2.元数据查询

Select version()；服务器版本信息
Select database()；当前数据库名
Select user():当前用户名
Show status;服务器状态
Show variables;服务器配置变量
Show global variables like ‘%datadir%‘：看数据文件存放位置
show global variables like ‘%datadir%’; 看数据文件存放位置
select @@datadir; 查询数据库的路径
select @@basedir 查询mysql的安装路径

3.union查询详解

把2条或者多条SQL语句的查询结果合并成一个结果集

• 比如：sql1: N行，sql2: M行，sql1 union sql2 —> N+M行

mysql> select * from temp1;
+-----+-------+
| uid | uname |
+-----+-------+
|   1 | haha  |
|   2 | xixi  |
|   3 | hehe  |
+-----+-------+
3 rows in set (0.00 sec)

mysql> select * from temp2;
+-----+-----+
| eid | age |
+-----+-----+
|   1 |  21 |
|   2 |  20 |
|   3 |  14 |
+-----+-----+
3 rows in set (0.00 sec)

mysql> select * from temp1 union select * from temp2;
+-----+-------+
| uid | uname |
+-----+-------+
|   1 | haha  |
|   2 | xixi  |
|   3 | hehe  |
|   1 | 21    |
|   2 | 20    |
|   3 | 14    |
+-----+-------+
6 rows in set (0.00 sec)

mysql> select * from temp1 union select  1,2;
+-----+-------+
| uid | uname |
+-----+-------+
|   1 | haha  |
|   2 | xixi  |
|   3 | hehe  |
|   1 | 2     |
+-----+-------+
4 rows in set (0.00 sec)
mysql> select * from temp1 union select  12,2;
+-----+-------+
| uid | uname |
+-----+-------+
|   1 | haha  |
|   2 | xixi  |
|   3 | hehe  |
|  12 | 2     |
+-----+-------+
4 rows in set (0.00 sec)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53

• 要求结果集中的列数一致就可以。一般就是2列或者多列

4.分组查询展示

GROUP_CONCAT()

• 是将分组中括号里对应的字符串进行连接.如果分组中括号里的参数xxx有多行，那么就会将这多行的字符串连接，每个字符串之间会有特定的符号进行分隔。
• 格式：

group_concat( [distinct] 要连接的字段 [order by 排序字段 asc/desc ] [separator '分隔符'] )

1
2
3

select sid,group_concat(cid),group_concat(cj order by cj desc SEPARATOR ' ') from score
group by sid
1
2

5.字符串函数

mysql> select lower("ABcd");
ERROR 2006 (HY000): MySQL server has gone away
No connection. Trying to reconnect...
Connection id:    14
Current database: sys

+---------------+
| lower("ABcd") |
+---------------+
| abcd          |
+---------------+
1 row in set (0.01 sec)

mysql> select upper("ABcd");
+---------------+
| upper("ABcd") |
+---------------+
| ABCD          |
+---------------+
1 row in set (0.00 sec)

mysql> select concat('abc','123');
+---------------------+
| concat('abc','123') |
+---------------------+
| abc123              |
+---------------------+
1 row in set (0.02 sec)

mysql> select concat_ws(':','abc','123');
+----------------------------+
| concat_ws(':','abc','123') |
+----------------------------+
| abc:123                    |
+----------------------------+
1 row in set (0.00 sec)

mysql> select substr('hello',2,3);
+---------------------+
| substr('hello',2,3) |
+---------------------+
| ell                 |
+---------------------+
1 row in set (0.00 sec)

mysql> select substr('hello',2,1);
+---------------------+
| substr('hello',2,1) |
+---------------------+
| e                   |
+---------------------+
1 row in set (0.00 sec)

mysql> select length('hello');
+-----------------+
| length('hello') |
+-----------------+
|               5 |
+-----------------+
1 row in set (0.00 sec)

mysql> select char_length('hello');
+----------------------+
| char_length('hello') |
+----------------------+
|                    5 |
+----------------------+
1 row in set (0.00 sec)

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69

6.mysql数据库导入导出

• 表数据导入导出
  • 导出TXT文件（有漏洞，mysql已经封了）

select * from demo1 into outfile '/temp/utemp1data.txt';
use student;
show VARIABLES like "secure_file_priv";
1
2
3

---

mysql> show VARIABLES like "secure_file_priv";
+------------------+-------+
| Variable_name    | Value |
+------------------+-------+
| secure_file_priv | NULL  |
+------------------+-------+
1 row in set, 1 warning (0.00 sec)
可以看到没有权限
1
2
3
4
5
6
7
8

• 导出TXT文件

oad data local infile '/root/utemp1data.txt' into table temp;
1

• 数据库导入导出
  –mysqldump导出
  – dump出表utemp1
  – mysqldump -uroot -p student utemp1>utemp1.sql
  – dump出库student
  – mysqldump -uroot -p student>student.sql
  – dump所有的数据库及数据库表
  – mysqldump -u root -p --all-databases>mysqldatabases.sql;

– mysql的数据库导入"<"
– 新建一个数据库
create database dumpdemo1
– 回到mysql接口
– mysql -u root -p654321 dumpdemo1<student.sql
– 进入mysql验证
use dumpdemo1
show tables;

– mysql的数据库导入 “source”
mysql -u root -p
create database sourcedumpdemo;
source /var/lib/mysql-files/student.sql