数据操作
可以通过SQL语句中的DML语言来实现数据的操作，包括
- 使用INSERT实现数据的插入
- UPDATE实现数据的更新
- 使用DELETE实现数据的删除
- 使用SELECT查询数据以及。
数据的增删改查
插入数据INSERT
1. 插入完整数据（顺序插入）
语法一：
INSERT INTO 表名(字段1,字段2,字段3…字段n) VALUES(值1,值2,值3…值n);
语法二：
INSERT INTO 表名 VALUES (值1,值2,值3…值n);
2. 指定字段插入数据
语法：
INSERT INTO 表名(字段1,字段2,字段3…) VALUES (值1,值2,值3…);
3. 插入多条记录
语法：
INSERT INTO 表名 VALUES
(值1,值2,值3…值n),
(值1,值2,值3…值n),
(值1,值2,值3…值n);
4. 插入查询结果
语法：
INSERT INTO 表名(字段1,字段2,字段3…字段n)
SELECT (字段1,字段2,字段3…字段n) FROM 表2
WHERE …;
更新数据UPDATE
语法：
UPDATE 表名 SET
字段1=值1,
字段2=值2,
WHERE CONDITION;
示例：
UPDATE mysql.user SET password=password(‘123’)
where user=’root’ and host=’localhost’;
删除数据DELETE
语法：
DELETE FROM 表名
WHERE CONITION;
示例：
DELETE FROM mysql.user
WHERE password=’’;
练习：
更新MySQL root用户密码为mysql123
删除除从本地登录的root用户以外的所有用户
单表查询
单表查询
select distinct 字段1,字段2,字段3 from 库.表
where 条件
group by 分组条件
having 过滤 having运行完之后不是去运行order，而是去运行distinct后边的字段，进行去重；distinct运行完之后再运行order by
order by 排序字段
limit n; 最后再运行limit
#########简单查询
mysql> use db5;
Database changed
mysql> desc employee;
+--------------+-----------------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+--------------+-----------------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| name | varchar(20) | NO | | NULL | |
| sex | enum(‘male‘,‘female‘) | NO | | male | |
| age | int(3) unsigned | NO | | 28 | |
| hire_date | date | NO | | NULL | |
| post | varchar(50) | YES | | NULL | |
| post_comment | varchar(100) | YES | | NULL | |
| salary | double(15,2) | YES | | NULL | |
| office | int(11) | YES | | NULL | |
| depart_id | int(11) | YES | | NULL | |
+--------------+-----------------------+------+-----+---------+----------------+
10 rows in set (0.00 sec)
10 rows in set (0.00 sec)
mysql> select * from employee;
+----+------------+--------+-----+------------+-----------------------------------------+--------------+------------+--------+-----------+
| id | name | sex | age | hire_date | post | post_comment | salary | office | depart_id |
+----+------------+--------+-----+------------+-----------------------------------------+--------------+------------+--------+-----------+
| 1 | egon | male | 18 | 2017-03-01 | 老男孩驻沙河办事处外交大使 | NULL | 7300.33 | 401 | 1 |
| 2 | alex | male | 78 | 2015-03-02 | teacher | NULL | 1000000.31 | 401 | 1 |
| 3 | wupeiqi | male | 81 | 2013-03-05 | teacher | NULL | 8300.00 | 401 | 1 |
| 4 | yuanhao | male | 73 | 2014-07-01 | teacher | NULL | 3500.00 | 401 | 1 |
| 5 | liwenzhou | male | 28 | 2012-11-01 | teacher | NULL | 2100.00 | 401 | 1 |
| 6 | jingliyang | female | 18 | 2011-02-11 | teacher | NULL | 9000.00 | 401 | 1 |
| 7 | jinxin | male | 18 | 1900-03-01 | teacher | NULL | 30000.00 | 401 | 1 |
| 8 | 成龙 | male | 48 | 2010-11-11 | teacher | NULL | 10000.00 | 401 | 1 |
| 9 | 歪歪 | female | 48 | 2015-03-11 | sale | NULL | 3000.13 | 402 | 2 |
| 10 | 丫丫 | female | 38 | 2010-11-01 | sale | NULL | 2000.35 | 402 | 2 |
| 11 | 丁丁 | female | 18 | 2011-03-12 | sale | NULL | 1000.37 | 402 | 2 |
| 12 | 星星 | female | 18 | 2016-05-13 | sale | NULL | 3000.29 | 402 | 2 |
| 13 | 格格 | female | 28 | 2017-01-27 | sale | NULL | 4000.33 | 402 | 2 |
| 14 | 张野 | male | 28 | 2016-03-11 | operation | NULL | 10000.13 | 403 | 3 |
| 15 | 程咬金 | male | 18 | 1997-03-12 | operation | NULL | 20000.00 | 403 | 3 |
| 16 | 程咬银 | female | 18 | 2013-03-11 | operation | NULL | 19000.00 | 403 | 3 |
| 17 | 程咬铜 | male | 18 | 2015-04-11 | operation | NULL | 18000.00 | 403 | 3 |
| 18 | 程咬铁 | female | 18 | 2014-05-12 | operation | NULL | 17000.00 | 403 | 3 |
+----+------------+--------+-----+------------+-----------------------------------------+--------------+------------+--------+-----------+
18 rows in set (0.00 sec)
mysql> select id,name,salary from employee; +----+------------+------------+ | id | name | salary | +----+------------+------------+ | 1 | egon | 7300.33 | | 2 | alex | 1000000.31 | | 3 | wupeiqi | 8300.00 | | 4 | yuanhao | 3500.00 | | 5 | liwenzhou | 2100.00 | | 6 | jingliyang | 9000.00 | | 7 | jinxin | 30000.00 | | 8 | 成龙 | 10000.00 | | 9 | 歪歪 | 3000.13 | | 10 | 丫丫 | 2000.35 | | 11 | 丁丁 | 1000.37 | | 12 | 星星 | 3000.29 | | 13 | 格格 | 4000.33 | | 14 | 张野 | 10000.13 | | 15 | 程咬金 | 20000.00 | | 16 | 程咬银 | 19000.00 | | 17 | 程咬铜 | 18000.00 | | 18 | 程咬铁 | 17000.00 | +----+------------+------------+ 18 rows in set (0.00 sec) mysql> select post from employee; +-----------------------------------------+ | post | +-----------------------------------------+ | 老男孩驻沙河办事处外交大使 | | teacher | | teacher | | teacher | | teacher | | teacher | | teacher | | teacher | | sale | | sale | | sale | | sale | | sale | | operation | | operation | | operation | | operation | | operation | +-----------------------------------------+ 18 rows in set (0.00 sec) mysql> select distinct post from employee; ##distinct是避免重复 +-----------------------------------------+ | post | +-----------------------------------------+ | 老男孩驻沙河办事处外交大使 | | teacher | | sale | | operation | +-----------------------------------------+ 4 rows in set (0.08 sec) mysql> select name,salary*12 from employee; ##通过四则运算查询 +------------+-------------+ | name | salary*12 | +------------+-------------+ | egon | 87603.96 | | alex | 12000003.72 | | wupeiqi | 99600.00 | | yuanhao | 42000.00 | | liwenzhou | 25200.00 | | jingliyang | 108000.00 | | jinxin | 360000.00 | | 成龙 | 120000.00 | | 歪歪 | 36001.56 | | 丫丫 | 24004.20 | | 丁丁 | 12004.44 | | 星星 | 36003.48 | | 格格 | 48003.96 | | 张野 | 120001.56 | | 程咬金 | 240000.00 | | 程咬银 | 228000.00 | | 程咬铜 | 216000.00 | | 程咬铁 | 204000.00 | +------------+-------------+ 18 rows in set (0.09 sec) mysql> select name,salary*12 annual_salary from employee; +------------+---------------+ | name | annual_salary | +------------+---------------+ | egon | 87603.96 | | alex | 12000003.72 | | wupeiqi | 99600.00 | | yuanhao | 42000.00 | | liwenzhou | 25200.00 | | jingliyang | 108000.00 | | jinxin | 360000.00 | | 成龙 | 120000.00 | | 歪歪 | 36001.56 | | 丫丫 | 24004.20 | | 丁丁 | 12004.44 | | 星星 | 36003.48 | | 格格 | 48003.96 | | 张野 | 120001.56 | | 程咬金 | 240000.00 | | 程咬银 | 228000.00 | | 程咬铜 | 216000.00 | | 程咬铁 | 204000.00 | +------------+---------------+ 18 rows in set (0.00 sec) mysql> select concat(‘姓名:‘, name, ‘性别:‘, sex)as info from employee; ##concat通常用于连接字符串 +--------------------------------+ | info | +--------------------------------+ | 姓名:egon性别:male | | 姓名:alex性别:male | | 姓名:wupeiqi性别:male | | 姓名:yuanhao性别:male | | 姓名:liwenzhou性别:male | | 姓名:jingliyang性别:female | | 姓名:jinxin性别:male | | 姓名:成龙性别:male | | 姓名:歪歪性别:female | | 姓名:丫丫性别:female | | 姓名:丁丁性别:female | | 姓名:星星性别:female | | 姓名:格格性别:female | | 姓名:张野性别:male | | 姓名:程咬金性别:male | | 姓名:程咬银性别:female | | 姓名:程咬铜性别:male | | 姓名:程咬铁性别:female | +--------------------------------+ 18 rows in set (0.14 sec) mysql> select concat(‘姓名:‘, name, ‘性别:‘, sex) as info, concat(‘年薪:‘, salar y*12) as annual_salary from employee; +--------------------------------+--------------------+ | info | annual_salary | +--------------------------------+--------------------+ | 姓名:egon性别:male | 年薪:87603.96 | | 姓名:alex性别:male | 年薪:12000003.72 | | 姓名:wupeiqi性别:male | 年薪:99600.00 | | 姓名:yuanhao性别:male | 年薪:42000.00 | | 姓名:liwenzhou性别:male | 年薪:25200.00 | | 姓名:jingliyang性别:female | 年薪:108000.00 | | 姓名:jinxin性别:male | 年薪:360000.00 | | 姓名:成龙性别:male | 年薪:120000.00 | | 姓名:歪歪性别:female | 年薪:36001.56 | | 姓名:丫丫性别:female | 年薪:24004.20 | | 姓名:丁丁性别:female | 年薪:12004.44 | | 姓名:星星性别:female | 年薪:36003.48 | | 姓名:格格性别:female | 年薪:48003.96 | | 姓名:张野性别:male | 年薪:120001.56 | | 姓名:程咬金性别:male | 年薪:240000.00 | | 姓名:程咬银性别:female | 年薪:228000.00 | | 姓名:程咬铜性别:male | 年薪:216000.00 | | 姓名:程咬铁性别:female | 年薪:204000.00 | +--------------------------------+--------------------+ 18 rows in set (0.00 sec) mysql> select * from employee;
+----+------------+--------+-----+------------+-----------------------------------------+--------------+------------+--------+-----------+
| id | name | sex | age | hire_date | post | post_comment | salary | office | depart_id |
+----+------------+--------+-----+------------+-----------------------------------------+--------------+------------+--------+-----------+
| 1 | egon | male | 18 | 2017-03-01 | 老男孩驻沙河办事处外交大使 | NULL | 7300.33 | 401 | 1 |
| 2 | alex | male | 78 | 2015-03-02 | teacher | NULL | 1000000.31 | 401 | 1 |
| 3 | wupeiqi | male | 81 | 2013-03-05 | teacher | NULL | 8300.00 | 401 | 1 |
| 4 | yuanhao | male | 73 | 2014-07-01 | teacher | NULL | 3500.00 | 401 | 1 |
| 5 | liwenzhou | male | 28 | 2012-11-01 | teacher | NULL | 2100.00 | 401 | 1 |
| 6 | jingliyang | female | 18 | 2011-02-11 | teacher | NULL | 9000.00 | 401 | 1 |
| 7 | jinxin | male | 18 | 1900-03-01 | teacher | NULL | 30000.00 | 401 | 1 |
| 8 | 成龙 | male | 48 | 2010-11-11 | teacher | NULL | 10000.00 | 401 | 1 |
| 9 | 歪歪 | female | 48 | 2015-03-11 | sale | NULL | 3000.13 | 402 | 2 |
| 10 | 丫丫 | female | 38 | 2010-11-01 | sale | NULL | 2000.35 | 402 | 2 |
| 11 | 丁丁 | female | 18 | 2011-03-12 | sale | NULL | 1000.37 | 402 | 2 |
| 12 | 星星 | female | 18 | 2016-05-13 | sale | NULL | 3000.29 | 402 | 2 |
| 13 | 格格 | female | 28 | 2017-01-27 | sale | NULL | 4000.33 | 402 | 2 |
| 14 | 张野 | male | 28 | 2016-03-11 | operation | NULL | 10000.13 | 403 | 3 |
| 15 | 程咬金 | male | 18 | 1997-03-12 | operation | NULL | 20000.00 | 403 | 3 |
| 16 | 程咬银 | female | 18 | 2013-03-11 | operation | NULL | 19000.00 | 403 | 3 |
| 17 | 程咬铜 | male | 18 | 2015-04-11 | operation | NULL | 18000.00 | 403 | 3 |
| 18 | 程咬铁 | female | 18 | 2014-05-12 | operation | NULL | 17000.00 | 403 | 3 |
+----+------------+--------+-----+------------+-----------------------------------------+--------------+------------+--------+-----------+
18 rows in set (0.00 sec) mysql> select concat(name, ‘:‘, age)from employee; +------------------------+ | concat(name, ‘:‘, age) | +------------------------+ | egon:18 | | alex:78 | | wupeiqi:81 | | yuanhao:73 | | liwenzhou:28 | | jingliyang:18 | | jinxin:18 | | 成龙:48 | | 歪歪:48 | | 丫丫:38 | | 丁丁:18 | | 星星:18 | | 格格:28 | | 张野:28 | | 程咬金:18 | | 程咬银:18 | | 程咬铜:18 | | 程咬铁:18 | +------------------------+ 18 rows in set (0.00 sec) mysql> select concat_ws(‘:‘, name, sex, age) from employee; ##concat_ws（）第一个参数为分隔符 +--------------------------------+ | concat_ws(‘:‘, name, sex, age) | +--------------------------------+ | egon:male:18 | | alex:male:78 | | wupeiqi:male:81 | | yuanhao:male:73 | | liwenzhou:male:28 | | jingliyang:female:18 | | jinxin:male:18 | | 成龙:male:48 | | 歪歪:female:48 | | 丫丫:female:38 | | 丁丁:female:18 | | 星星:female:18 | | 格格:female:28 | | 张野:male:28 | | 程咬金:male:18 | | 程咬银:female:18 | | 程咬铜:male:18 | | 程咬铁:female:18 | +--------------------------------+ 18 rows in set (0.00 sec)
练习：1 查出所有员工的名字，薪资,格式为
<名字:egon> <薪资:3000>
2 查出所有的岗位（去掉重复）
3 查出所有员工名字，以及他们的年薪,年薪的字段名为annual_year
mysql> select concat(‘<名字>:‘, name, ‘>‘)from employee; +--------------------------------+ | concat(‘<名字>:‘, name, ‘>‘) | +--------------------------------+ | <名字>:egon> | | <名字>:alex> | | <名字>:wupeiqi> | | <名字>:yuanhao> | | <名字>:liwenzhou> | | <名字>:jingliyang> | | <名字>:jinxin> | | <名字>:成龙> | | <名字>:歪歪> | | <名字>:丫丫> | | <名字>:丁丁> | | <名字>:星星> | | <名字>:格格> | | <名字>:张野> | | <名字>:程咬金> | | <名字>:程咬银> | | <名字>:程咬铜> | | <名字>:程咬铁> | +--------------------------------+ 18 rows in set (0.00 sec) mysql> select concat(‘<名字>:‘, name, ‘>‘), concat(‘<薪资:‘, salary, ‘>‘) f mployee; +--------------------------------+---------------------------------+ | concat(‘<名字>:‘, name, ‘>‘) | concat(‘<薪资:‘, salary, ‘>‘) | +--------------------------------+---------------------------------+ | <名字>:egon> | <薪资:7300.33> | | <名字>:alex> | <薪资:1000000.31> | | <名字>:wupeiqi> | <薪资:8300.00> | | <名字>:yuanhao> | <薪资:3500.00> | | <名字>:liwenzhou> | <薪资:2100.00> | | <名字>:jingliyang> | <薪资:9000.00> | | <名字>:jinxin> | <薪资:30000.00> | | <名字>:成龙> | <薪资:10000.00> | | <名字>:歪歪> | <薪资:3000.13> | | <名字>:丫丫> | <薪资:2000.35> | | <名字>:丁丁> | <薪资:1000.37> | | <名字>:星星> | <薪资:3000.29> | | <名字>:格格> | <薪资:4000.33> | | <名字>:张野> | <薪资:10000.13> | | <名字>:程咬金> | <薪资:20000.00> | | <名字>:程咬银> | <薪资:19000.00> | | <名字>:程咬铜> | <薪资:18000.00> | | <名字>:程咬铁> | <薪资:17000.00> | +--------------------------------+---------------------------------+ 18 rows in set (0.00 sec)
#where约束 select id,name,age from employee where id > 7; #单条件 select name,post,salary from employee where post=‘teacher‘ and salary > 8000; select name,salary from employee where salary >= 20000 and salary <= 30000; select name,salary from employee where salary between 20000 and 30000; select name,salary from employee where salary < 20000 or salary > 30000; select name,salary from employee where salary not between 20000 and 30000; select * from employee where age = 73 or age = 81 or age = 28; select * from employee where age in (73,81,28); select * from employee where post_comment is Null; #判断是否为空 select * from employee where post_comment is not Null; select * from employee where name like "jin%"; #模糊匹配 %代表任意多个字符，jin开头的不管后边是什么 select * from employee where name like "jin___"; ##___三个下划线代表3个任意字符
mysql> select id,name,age from employee where id > 7; +----+-----------+-----+ | id | name | age | +----+-----------+-----+ | 8 | 成龙 | 48 | | 9 | 歪歪 | 48 | | 10 | 丫丫 | 38 | | 11 | 丁丁 | 18 | | 12 | 星星 | 18 | | 13 | 格格 | 28 | | 14 | 张野 | 28 | | 15 | 程咬金 | 18 | | 16 | 程咬银 | 18 | | 17 | 程咬铜 | 18 | | 18 | 程咬铁 | 18 | +----+-----------+-----+ 11 rows in set (0.13 sec) mysql> select name,post,salary from employee where post=‘teacher‘ and salary > 8 000; +------------+---------+------------+ | name | post | salary | +------------+---------+------------+ | alex | teacher | 1000000.31 | | wupeiqi | teacher | 8300.00 | | jingliyang | teacher | 9000.00 | | jinxin | teacher | 30000.00 | | 成龙 | teacher | 10000.00 | +------------+---------+------------+ 5 rows in set (0.04 sec) mysql> select name,salary from employee where salary >=20000 and salary <=30000; +-----------+----------+ | name | salary | +-----------+----------+ | jinxin | 30000.00 | | 程咬金 | 20000.00 | +-----------+----------+ 2 rows in set (0.00 sec) mysql> select name,salary from employee where salary between 20000 and 30000; +-----------+----------+ | name | salary | +-----------+----------+ | jinxin | 30000.00 | | 程咬金 | 20000.00 | +-----------+----------+ 2 rows in set (0.07 sec) mysql> select name,salary from employee where salary < 20000 or salary > 30000; +------------+------------+ | name | salary | +------------+------------+ | egon | 7300.33 | | alex | 1000000.31 | | wupeiqi | 8300.00 | | yuanhao | 3500.00 | | liwenzhou | 2100.00 | | jingliyang | 9000.00 | | 成龙 | 10000.00 | | 歪歪 | 3000.13 | | 丫丫 | 2000.35 | | 丁丁 | 1000.37 | | 星星 | 3000.29 | | 格格 | 4000.33 | | 张野 | 10000.13 | | 程咬银 | 19000.00 | | 程咬铜 | 18000.00 | | 程咬铁 | 17000.00 | +------------+------------+ 16 rows in set (0.01 sec) mysql> select name,salary from employee where salary not between 20000 and 30000 ; +------------+------------+ | name | salary | +------------+------------+ | egon | 7300.33 | | alex | 1000000.31 | | wupeiqi | 8300.00 | | yuanhao | 3500.00 | | liwenzhou | 2100.00 | | jingliyang | 9000.00 | | 成龙 | 10000.00 | | 歪歪 | 3000.13 | | 丫丫 | 2000.35 | | 丁丁 | 1000.37 | | 星星 | 3000.29 | | 格格 | 4000.33 | | 张野 | 10000.13 | | 程咬银 | 19000.00 | | 程咬铜 | 18000.00 | | 程咬铁 | 17000.00 | +------------+------------+ 16 rows in set (0.00 sec) mysql> select * from employee where age =73 or age = 81 or age = 28;
+----+-----------+--------+-----+------------+-----------+--------------+----------+--------+-----------+
| id | name | sex | age | hire_date | post | post_comment | salary | office | depart_id |
+----+-----------+--------+-----+------------+-----------+--------------+----------+--------+-----------+
| 3 | wupeiqi | male | 81 | 2013-03-05 | teacher | NULL | 8300.00 | 401 | 1 |
| 4 | yuanhao | male | 73 | 2014-07-01 | teacher | NULL | 3500.00 | 401 | 1 |
| 5 | liwenzhou | male | 28 | 2012-11-01 | teacher | NULL | 2100.00 | 401 | 1 |
| 13 | 格格 | female | 28 | 2017-01-27 | sale | NULL | 4000.33 | 402 | 2 |
| 14 | 张野 | male | 28 | 2016-03-11 | operation | NULL | 10000.13 | 403 | 3 |
+----+-----------+--------+-----+------------+-----------+--------------+----------+--------+-----------+
5 rows in set (0.00 sec) mysql> select * from employee where post_comment is Null;
+----+------------+--------+-----+------------+-----------------------------------------+--------------+------------+--------+-----------+
| id | name | sex | age | hire_date | post | post_comment | salary | office | depart_id |
+----+------------+--------+-----+------------+-----------------------------------------+--------------+------------+--------+-----------+
| 1 | egon | male | 18 | 2017-03-01 | 老男孩驻沙河办事处外交大使 | NULL | 7300.33 | 401 | 1 |
| 2 | alex | male | 78 | 2015-03-02 | teacher | NULL | 1000000.31 | 401 | 1 |
| 3 | wupeiqi | male | 81 | 2013-03-05 | teacher | NULL | 8300.00 | 401 | 1 |
| 4 | yuanhao | male | 73 | 2014-07-01 | teacher | NULL | 3500.00 | 401 | 1 |
| 5 | liwenzhou | male | 28 | 2012-11-01 | teacher | NULL | 2100.00 | 401 | 1 |
| 6 | jingliyang | female | 18 | 2011-02-11 | teacher | NULL | 9000.00 | 401 | 1 |
| 7 | jinxin | male | 18 | 1900-03-01 | teacher | NULL | 30000.00 | 401 | 1 |
| 8 | 成龙 | male | 48 | 2010-11-11 | teacher | NULL | 10000.00 | 401 | 1 |
| 9 | 歪歪 | female | 48 | 2015-03-11 | sale | NULL | 3000.13 | 402 | 2 |
| 10 | 丫丫 | female | 38 | 2010-11-01 | sale | NULL | 2000.35 | 402 | 2 |
| 11 | 丁丁 | female | 18 | 2011-03-12 | sale | NULL | 1000.37 | 402 | 2 |
| 12 | 星星 | female | 18 | 2016-05-13 | sale | NULL | 3000.29 | 402 | 2 |
| 13 | 格格 | female | 28 | 2017-01-27 | sale | NULL | 4000.33 | 402 | 2 |
| 14 | 张野 | male | 28 | 2016-03-11 | operation | NULL | 10000.13 | 403 | 3 |
| 15 | 程咬金 | male | 18 | 1997-03-12 | operation | NULL | 20000.00 | 403 | 3 |
| 16 | 程咬银 | female | 18 | 2013-03-11 | operation | NULL | 19000.00 | 403 | 3 |
| 17 | 程咬铜 | male | 18 | 2015-04-11 | operation | NULL | 18000.00 | 403 | 3 |
| 18 | 程咬铁 | female | 18 | 2014-05-12 | operation | NULL | 17000.00 | 403 | 3 |
+----+------------+--------+-----+------------+-----------------------------------------+--------------+------------+--------+-----------+
18 rows in set (0.00 sec) mysql> select * from employee where name like "jin%"; +----+------------+--------+-----+------------+---------+--------------+-------- --+--------+-----------+ | id | name | sex | age | hire_date | post | post_comment | salary | office | depart_id | +----+------------+--------+-----+------------+---------+--------------+-------- --+--------+-----------+ | 6 | jingliyang | female | 18 | 2011-02-11 | teacher | NULL | 9000.0 0 | 401 | 1 | | 7 | jinxin | male | 18 | 1900-03-01 | teacher | NULL | 30000.0 0 | 401 | 1 | +----+------------+--------+-----+------------+---------+--------------+-------- --+--------+-----------+ 2 rows in set (0.09 sec) mysql> select * from employee where name like "jin___"; +----+--------+------+-----+------------+---------+--------------+----------+--- -----+-----------+ | id | name | sex | age | hire_date | post | post_comment | salary | of fice | depart_id | +----+--------+------+-----+------------+---------+--------------+----------+--- -----+-----------+ | 7 | jinxin | male | 18 | 1900-03-01 | teacher | NULL | 30000.00 | 401 | 1 | +----+--------+------+-----+------------+---------+--------------+----------+--- -----+-----------+ 1 row in set (0.00 sec)
group by 分组查询 #group by分组 在where之后运行分组就是按照相应字段进行归类，每后边那个字就是要分的字段 mysql> set global sql_mode="ONLY_FULL_GROUP_BY"; 分组之后，只能取分组的字段，以及每个组 聚合的结果 select post from employee group by post;
单独使用GROUP BY关键字分组
SELECT post FROM employee GROUP BY post;
注意：我们按照post字段分组，那么select查询的字段只能是post，想要获取组内的其他相关信息，需要借助函数
GROUP BY关键字和GROUP_CONCAT()函数一起使用
SELECT post,GROUP_CONCAT(name) FROM employee GROUP BY post;#按照岗位分组，并查看组内成员名
SELECT post,GROUP_CONCAT(name) as emp_members FROM employee GROUP BY post;
GROUP BY与聚合函数一起使用
select post,count(id) as count from employee group by post;#按照岗位分组，并查看每个组有多少人
#聚合函数 #以组为单位进行统计，不再考虑个人 max min avg sum count select post,count(id) as emp_count from employee group by post;##每个部门/职位有多少个员工；先确定你的表 select post,max(salary) as emp_max from employee group by post; select post,min(salary) as emp_min from employee group by post; select post,avg(salary) as emp_avg from employee group by post; select post,sum(age) as emp_sum from employee group by post;
mysql> select * from employee group by post;
+----+--------+--------+-----+------------+-----------------------------------------+--------------+------------+--------+-----------+
| id | name | sex | age | hire_date | post | post_comment | salary | office | depart_id |
+----+--------+--------+-----+------------+-----------------------------------------+--------------+------------+--------+-----------+
| 14 | 张野 | male | 28 | 2016-03-11 | operation | NULL | 10000.13 | 403 | 3 |
| 9 | 歪歪 | female | 48 | 2015-03-11 | sale | NULL | 3000.13 | 402 | 2 |
| 2 | alex | male | 78 | 2015-03-02 | teacher | NULL | 1000000.31 | 401 | 1 |
| 1 | egon | male | 18 | 2017-03-01 | 老男孩驻沙河办事处外交大使 | NULL | 7300.33 | 401 | 1 |
+----+--------+--------+-----+------------+-----------------------------------------+--------------+------------+--------+-----------+
4 rows in set (0.08 sec)
#由于没有设置ONLY_FULL_GROUP_BY,于是也可以有结果，默认都是组内的第一条记录，但其实这是没有意义的mysql> set global sql_mode="ONLY_FULL_GROUP_BY"; Query OK, 0 rows affected (0.11 sec) mysql> exit Bye C:\Users\Administrator>mysql -uroot -p; Warning: Using a password on the command line interface can be insecure. ERROR 1045 (28000): Access denied for user ‘root‘@‘localhost‘ (using password: Y ES) C:\Users\Administrator>mysql -uroot -p Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 5 Server version: 5.6.39 MySQL Community Server (GPL) Copyright (c) 2000, 2018, 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> use db5; Database changed mysql> select * from employee group by post; ERROR 1055 (42000): ‘db5.employee.id‘ isn‘t in GROUP BY mysql> select post from employee group by post; +-----------------------------------------+ | post | +-----------------------------------------+ | operation | | sale | | teacher | | 老男孩驻沙河办事处外交大使 | +-----------------------------------------+ 4 rows in set (0.00 sec) mysql> select post,count(id) as emp_count from employee group by post; +-----------------------------------------+-----------+ | post | emp_count | +-----------------------------------------+-----------+ | operation | 5 | | sale | 5 | | teacher | 7 | | 老男孩驻沙河办事处外交大使 | 1 | +-----------------------------------------+-----------+ 4 rows in set (0.06 sec)
强调：如果我们用unique的字段作为分组的依据，则每一条记录自成一组，这种分组没有意义 多条记录之间的某个字段值相同，该字段通常用来作为分组的依据
#没有group by则默认整体算作一组 select max(salary) from employee; #取所有员工的最高工资 #group_concat 职位包含的所有员工成员的名字 select post,group_concat(name) from employee group by post;
mysql> select max(salary) from employee;
+-------------+
| max(salary) |
+-------------+
| 1000000.31 |
+-------------+
1 row in set (0.07 sec)
mysql> select post,group_concat(name) from employee group by post;
+-----------------------------------------+-------------------------------------
--------------------+
| post | group_concat(name)
|
+-----------------------------------------+-------------------------------------
--------------------+
| operation | 程咬铁,程咬铜,程咬银,程咬金,张野
|
| sale | 格格,星星,丁丁,丫丫,歪歪
|
| teacher | 成龙,jinxin,jingliyang,liwenzhou,yua
nhao,wupeiqi,alex |
| 老男孩驻沙河办事处外交大使 | egon
|
+-----------------------------------------+-------------------------------------
--------------------+
4 rows in set (0.01 sec)
#练习：
1. 查询岗位名以及岗位包含的所有员工名字 #先确定你查的是哪张表，有没有过滤条件where，有没有分组分类的； 2. 先取出年龄在50以上的然后再 查询岗位名以及各岗位内包含的员工个数 3. 查询公司内男员工和女员工的个数 4. 查询岗位名以及各岗位的平均薪资 5. 查询岗位名以及各岗位的最高薪资 6. 查询岗位名以及各岗位的最低薪资 7. 查询男员工与男员工的平均薪资，女员工与女员工的平均薪资
select post,group_concat(name) from employee group by post; select post,count(id) from employee where age > 50 group by post; select sex,count(id) from employee group by sex; select sex,avg(salary) from employee group by sex;
mysql> select post,group_concat(name) from employee group by post;
+-----------------------------------------+------------------------------------
--------------------+
| post | group_concat(name)
|
+-----------------------------------------+------------------------------------
--------------------+
| operation | 程咬铁,程咬铜,程咬银,程咬金,张野
|
| sale | 格格,星星,丁丁,丫丫,歪歪
|
| teacher | 成龙,jinxin,jingliyang,liwenzhou,yu
nhao,wupeiqi,alex |
| 老男孩驻沙河办事处外交大使 | egon
|
+-----------------------------------------+------------------------------------
--------------------+
4 rows in set (0.00 sec)
mysql> select post,count(id) from employee where age >50 group by post;
+---------+-----------+
| post | count(id) |
+---------+-----------+
| teacher | 3 |
+---------+-----------+
1 row in set (0.00 sec)
mysql> select sex,count(id) from employee group by sex;
+--------+-----------+
| sex | count(id) |
+--------+-----------+
| male | 10 |
| female | 8 |
+--------+-----------+
2 rows in set (0.00 sec)
mysql> select sex,avg(salary) from employee group by sex;
+--------+---------------+
| sex | avg(salary) |
+--------+---------------+
| male | 110920.077000 |
| female | 7250.183750 |
+--------+---------------+
2 rows in set (0.00 sec)
#having 过滤条件 在分组之后进行；where在分组之前
例如： 1. 查询各岗位内包含的员工个数小于2的岗位名、岗位内包含员工名字、个数 #聚合出员工个数 3. 查询各岗位平均薪资大于10000的岗位名、平均工资 4. 查询各岗位平均薪资大于10000且小于20000的岗位名、平均工资 and avg(salary) < 20000;
select post,group_concat(name),count(id) from employee group by post; select post,group_concat(name),count(id) from employee group by post having count(id) < 2; select post,avg(salary) from employee group by post having avg(salary) > 10000;
mysql> select post,group_concat(name), count(id) from employee group by post;
+-----------------------------------------+-------------------------------------
--------------------+-----------+
| post | group_concat(name)
| count(id) |
+-----------------------------------------+-------------------------------------
--------------------+-----------+
| operation | 程咬铁,程咬铜,程咬银,程咬金,张野
| 5 |
| sale | 格格,星星,丁丁,丫丫,歪歪
| 5 |
| teacher | 成龙,jinxin,jingliyang,liwenzhou,yua
nhao,wupeiqi,alex | 7 |
| 老男孩驻沙河办事处外交大使 | egon
| 1 |
+-----------------------------------------+-------------------------------------
--------------------+-----------+
4 rows in set (0.00 sec)
mysql> select post,group_concat(name),count(id) from employee group by post havi
ng count(id) < 2;
+-----------------------------------------+--------------------+-----------+
| post | group_concat(name) | count(id) |
+-----------------------------------------+--------------------+-----------+
| 老男孩驻沙河办事处外交大使 | egon | 1 |
+-----------------------------------------+--------------------+-----------+
1 row in set (0.01 sec)
mysql> select post,avg(salary) from employee group by post having avg(salary) >
-> \c
mysql> select post, avg(salary) from employee group by post having avg(salary) >
10000 and avg(salary) < 20000;
+-----------+--------------+
| post | avg(salary) |
+-----------+--------------+
| operation | 16800.026000 |
+-----------+--------------+
1 row in set (0.00 sec)
#order by 默认就是升序
select * from employee order by age asc; #升序，不加asc也可以
select * from employee order by age desc; #降序
select * from employee order by age asc,id desc; #先按照age升序排，如果age相同则按照id降序排；
聚合函数不能用在where内；分完组之后才能用聚合函数，having可以用；select max(salary) from employee 这里边运行max的时候就已经分组了； 先找表，再where再分组，...最后才打印select你想打印的内容
select distinct post,count(id) as emp_count from employee
where salary > 1000
group by post
having count(id) > 1 #在这个位置不能用emp_count>1，因为运行having之前还没运行distinct这个字段呢
order by emp_count desc #可以用count(id)，它是在分组之后干的；emp_count也可以用，因为order by 是在distinct后边运行；
;
mysql> select * from employee order by age asc, id desc;
+----+------------+--------+-----+------------+---------------------------------
--------+--------------+------------+--------+-----------+
| id | name | sex | age | hire_date | post
| post_comment | salary | office | depart_id |
+----+------------+--------+-----+------------+---------------------------------
--------+--------------+------------+--------+-----------+
| 18 | 程咬铁 | female | 18 | 2014-05-12 | operation
| NULL | 17000.00 | 403 | 3 |
| 17 | 程咬铜 | male | 18 | 2015-04-11 | operation
| NULL | 18000.00 | 403 | 3 |
| 16 | 程咬银 | female | 18 | 2013-03-11 | operation
| NULL | 19000.00 | 403 | 3 |
| 15 | 程咬金 | male | 18 | 1997-03-12 | operation
| NULL | 20000.00 | 403 | 3 |
| 12 | 星星 | female | 18 | 2016-05-13 | sale
| NULL | 3000.29 | 402 | 2 |
| 11 | 丁丁 | female | 18 | 2011-03-12 | sale
| NULL | 1000.37 | 402 | 2 |
| 7 | jinxin | male | 18 | 1900-03-01 | teacher
| NULL | 30000.00 | 401 | 1 |
| 6 | jingliyang | female | 18 | 2011-02-11 | teacher
| NULL | 9000.00 | 401 | 1 |
| 1 | egon | male | 18 | 2017-03-01 | 老男孩驻沙河办事处外交大使
| NULL | 7300.33 | 401 | 1 |
| 14 | 张野 | male | 28 | 2016-03-11 | operation
| NULL | 10000.13 | 403 | 3 |
| 13 | 格格 | female | 28 | 2017-01-27 | sale
| NULL | 4000.33 | 402 | 2 |
| 5 | liwenzhou | male | 28 | 2012-11-01 | teacher
| NULL | 2100.00 | 401 | 1 |
| 10 | 丫丫 | female | 38 | 2010-11-01 | sale
| NULL | 2000.35 | 402 | 2 |
| 9 | 歪歪 | female | 48 | 2015-03-11 | sale
| NULL | 3000.13 | 402 | 2 |
| 8 | 成龙 | male | 48 | 2010-11-11 | teacher
| NULL | 10000.00 | 401 | 1 |
| 4 | yuanhao | male | 73 | 2014-07-01 | teacher
| NULL | 3500.00 | 401 | 1 |
| 2 | alex | male | 78 | 2015-03-02 | teacher
| NULL | 1000000.31 | 401 | 1 |
| 3 | wupeiqi | male | 81 | 2013-03-05 | teacher
| NULL | 8300.00 | 401 | 1 |
+----+------------+--------+-----+------------+---------------------------------
--------+--------------+------------+--------+-----------+
18 rows in set (0.00 sec)
mysql> select distinct post, count(id) as emp_count from employee
-> where salary > 1000
-> group by post
-> having count(id) > 1
-> order by emp_count desc;
+-----------+-----------+
| post | emp_count |
+-----------+-----------+
| teacher | 7 |
| sale | 5 |
| operation | 5 |
+-----------+-----------+
3 rows in set (0.00 sec)
#limit限制打印条数 select * from employee limit 3; select * from employee order by salary desc limit 1; #找工资最高的那个人的详细信息 select * from employee limit 0,5; #从0开始往后再取5个；基本的分页功能 select * from employee limit 5,5; select * from employee limit 10,5; select * from employee limit 15,5;
mysql> select * from employee limit 3;
+----+---------+------+-----+------------+--------------------------------------
---+--------------+------------+--------+-----------+
| id | name | sex | age | hire_date | post
| post_comment | salary | office | depart_id |
+----+---------+------+-----+------------+--------------------------------------
---+--------------+------------+--------+-----------+
| 1 | egon | male | 18 | 2017-03-01 | 老男孩驻沙河办事处外交大使
| NULL | 7300.33 | 401 | 1 |
| 2 | alex | male | 78 | 2015-03-02 | teacher
| NULL | 1000000.31 | 401 | 1 |
| 3 | wupeiqi | male | 81 | 2013-03-05 | teacher
| NULL | 8300.00 | 401 | 1 |
+----+---------+------+-----+------------+--------------------------------------
---+--------------+------------+--------+-----------+
3 rows in set (0.00 sec)
mysql> select * from employee order by salary desc limit 1;
+----+------+------+-----+------------+---------+--------------+------------+---
-----+-----------+
| id | name | sex | age | hire_date | post | post_comment | salary | of
fice | depart_id |
+----+------+------+-----+------------+---------+--------------+------------+---
-----+-----------+
| 2 | alex | male | 78 | 2015-03-02 | teacher | NULL | 1000000.31 |
401 | 1 |
+----+------+------+-----+------------+---------+--------------+------------+---
-----+-----------+
1 row in set (0.00 sec)
mysql> select * from employee limit 0,5;
+----+-----------+------+-----+------------+------------------------------------
-----+--------------+------------+--------+-----------+
| id | name | sex | age | hire_date | post
| post_comment | salary | office | depart_id |
+----+-----------+------+-----+------------+------------------------------------
-----+--------------+------------+--------+-----------+
| 1 | egon | male | 18 | 2017-03-01 | 老男孩驻沙河办事处外交大使
| NULL | 7300.33 | 401 | 1 |
| 2 | alex | male | 78 | 2015-03-02 | teacher
| NULL | 1000000.31 | 401 | 1 |
| 3 | wupeiqi | male | 81 | 2013-03-05 | teacher
| NULL | 8300.00 | 401 | 1 |
| 4 | yuanhao | male | 73 | 2014-07-01 | teacher
| NULL | 3500.00 | 401 | 1 |
| 5 | liwenzhou | male | 28 | 2012-11-01 | teacher
| NULL | 2100.00 | 401 | 1 |
+----+-----------+------+-----+------------+------------------------------------
-----+--------------+------------+--------+-----------+
5 rows in set (0.00 sec)
#总结：
语法顺序：
select distinct 字段1,字段2,字段3 from 库.表
where 条件
group by 分组条件
having 过滤
order by 排序字段
limit n;
执行顺序：
def from(db,table):
f=open(r‘%s\%s‘ %(db,table)) #打开文件
return f #返回文件对象
def where(condition,f):
for line in f:
if condition:
yield line #满足条件再返回，不停地返回
def group(lines): #分组
pass
def having(group_res): #分组，拿到分组的结果
pass
def distinct(having_res): #拿到having_res的结果
pass
def order(distinct_res): #拿到distinct_res的结果
pass
def limit(order_res) #
pass
def select():
f=from(‘db1‘,‘t1‘) #找表
lines=where(‘id>3‘,f)
group_res=group(lines)
having_res=having(group_res)
distinct_res=distinct(having_res)
order_res=order(distinct_res)
res=limit(order_res)
print(res)
return res #返回值
#正则表达式 查询
select * from employee where name like ‘jin%‘;
select * from employee where name regexp ‘^jin‘; #以什么开头^
select * from employee where name regexp ‘^jin.*(g|n)$‘; # .*()以什么结尾 ，以g或者n结尾
mysql> select * from employee where name regexp ‘^jin‘; +----+------------+--------+-----+------------+---------+--------------+-------- --+--------+-----------+ | id | name | sex | age | hire_date | post | post_comment | salary | office | depart_id | +----+------------+--------+-----+------------+---------+--------------+-------- --+--------+-----------+ | 6 | jingliyang | female | 18 | 2011-02-11 | teacher | NULL | 9000.0 0 | 401 | 1 | | 7 | jinxin | male | 18 | 1900-03-01 | teacher | NULL | 30000.0 0 | 401 | 1 | +----+------------+--------+-----+------------+---------+--------------+-------- --+--------+-----------+ 2 rows in set (0.07 sec) mysql> select * from employee where name regexp ‘^jin.*(g|n)$‘; +----+------------+--------+-----+------------+---------+--------------+-------- --+--------+-----------+ | id | name | sex | age | hire_date | post | post_comment | salary | office | depart_id | +----+------------+--------+-----+------------+---------+--------------+-------- --+--------+-----------+ | 6 | jingliyang | female | 18 | 2011-02-11 | teacher | NULL | 9000.0 0 | 401 | 1 | | 7 | jinxin | male | 18 | 1900-03-01 | teacher | NULL | 30000.0 0 | 401 | 1 | +----+------------+--------+-----+------------+---------+--------------+-------- --+--------+-----------+ 2 rows in set (0.00 sec)
多表查询
把有关系的表连接合到一起
内连接：只取两张表的共同部分 select * from employee inner join department on employee.dep_id = department.id ; 左连接:在内连接的基础上保留左表的记录 select * from employee left join department on employee.dep_id = department.id ; 右连接：在内连接的基础上保留右表的记录 select * from employee right join department on employee.dep_id = department.id ; 全外连接：在内连接的基础上保留左右两表没有对应关系的记录 select * from employee full join department on employee.dep_id = department.id ; #mysql不支持full join select * from employee left join department on employee.dep_id = department.id union select * from employee right join department on employee.dep_id = department.id ;
笛卡尔积；在笛卡尔积的基础之中对表进行筛选，where，这就是连接；不要用where干，它是过滤的，有专门的方法
mysql> create database db6;
Query OK, 1 row affected (0.01 sec)
mysql> use db6;
Database changed
mysql> create table department(
-> id int,
-> name varchar(20)
-> );
Query OK, 0 rows affected (0.78 sec)
mysql> create table employee(
-> id int primary key auto_increment,
-> name varchar(20),
-> sex enum(‘male‘,‘female‘) not null default ‘male‘,
-> age int,
-> dep_id int
-> );
Query OK, 0 rows affected (1.05 sec)
mysql> insert into department values
-> (200,‘技术‘),
-> (201,‘人力资源‘),
-> (202,‘销售‘),
-> (203,‘运营‘);
Query OK, 4 rows affected (0.19 sec)
Records: 4 Duplicates: 0 Warnings: 0
mysql> insert into employee(name,sex,age,dep_id) values
-> (‘egon‘,‘male‘,18,200),
-> (‘alex‘,‘female‘,48,201),
-> (‘wupeiqi‘,‘male‘,38,201),
-> (‘yuanhao‘,‘female‘,28,202),
-> (‘liwenzhou‘,‘male‘,18,200),
-> (‘jingliyang‘,‘female‘,18,204)
-> ;
Query OK, 6 rows affected (0.15 sec)
Records: 6 Duplicates: 0 Warnings: 0
mysql> select * from employ;
ERROR 1146 (42S02): Table ‘db6.employ‘ doesn‘t exist
mysql> select * from department;
+------+--------------+
| id | name |
+------+--------------+
| 200 | 技术 |
| 201 | 人力资源 |
| 202 | 销售 |
| 203 | 运营 |
+------+--------------+
4 rows in set (0.00 sec)
mysql> select * from employee;
+----+------------+--------+------+--------+
| id | name | sex | age | dep_id |
+----+------------+--------+------+--------+
| 1 | egon | male | 18 | 200 |
| 2 | alex | female | 48 | 201 |
| 3 | wupeiqi | male | 38 | 201 |
| 4 | yuanhao | female | 28 | 202 |
| 5 | liwenzhou | male | 18 | 200 |
| 6 | jingliyang | female | 18 | 204 |
+----+------------+--------+------+--------+
6 rows in set (0.00 sec)
mysql> select * from employee,department;
+----+------------+--------+------+--------+------+--------------+
| id | name | sex | age | dep_id | id | name |
+----+------------+--------+------+--------+------+--------------+
| 1 | egon | male | 18 | 200 | 200 | 技术 |
| 1 | egon | male | 18 | 200 | 201 | 人力资源 |
| 1 | egon | male | 18 | 200 | 202 | 销售 |
| 1 | egon | male | 18 | 200 | 203 | 运营 |
| 2 | alex | female | 48 | 201 | 200 | 技术 |
| 2 | alex | female | 48 | 201 | 201 | 人力资源 |
| 2 | alex | female | 48 | 201 | 202 | 销售 |
| 2 | alex | female | 48 | 201 | 203 | 运营 |
| 3 | wupeiqi | male | 38 | 201 | 200 | 技术 |
| 3 | wupeiqi | male | 38 | 201 | 201 | 人力资源 |
| 3 | wupeiqi | male | 38 | 201 | 202 | 销售 |
| 3 | wupeiqi | male | 38 | 201 | 203 | 运营 |
| 4 | yuanhao | female | 28 | 202 | 200 | 技术 |
| 4 | yuanhao | female | 28 | 202 | 201 | 人力资源 |
| 4 | yuanhao | female | 28 | 202 | 202 | 销售 |
| 4 | yuanhao | female | 28 | 202 | 203 | 运营 |
| 5 | liwenzhou | male | 18 | 200 | 200 | 技术 |
| 5 | liwenzhou | male | 18 | 200 | 201 | 人力资源 |
| 5 | liwenzhou | male | 18 | 200 | 202 | 销售 |
| 5 | liwenzhou | male | 18 | 200 | 203 | 运营 |
| 6 | jingliyang | female | 18 | 204 | 200 | 技术 |
| 6 | jingliyang | female | 18 | 204 | 201 | 人力资源 |
| 6 | jingliyang | female | 18 | 204 | 202 | 销售 |
| 6 | jingliyang | female | 18 | 204 | 203 | 运营 |
+----+------------+--------+------+--------+------+--------------+
24 rows in set (0.07 sec)
mysql> select * from employee inner join department on employee.dep_id = department.id ;
+----+-----------+--------+------+--------+------+--------------+
| id | name | sex | age | dep_id | id | name |
+----+-----------+--------+------+--------+------+--------------+
| 1 | egon | male | 18 | 200 | 200 | 技术 |
| 2 | alex | female | 48 | 201 | 201 | 人力资源 |
| 3 | wupeiqi | male | 38 | 201 | 201 | 人力资源 |
| 4 | yuanhao | female | 28 | 202 | 202 | 销售 |
| 5 | liwenzhou | male | 18 | 200 | 200 | 技术 |
+----+-----------+--------+------+--------+------+--------------+
5 rows in set (0.00 sec)
mysql> select * from employee left join department on employee.dep_id = department.id ;
+----+------------+--------+------+--------+------+--------------+
| id | name | sex | age | dep_id | id | name |
+----+------------+--------+------+--------+------+--------------+
| 1 | egon | male | 18 | 200 | 200 | 技术 |
| 5 | liwenzhou | male | 18 | 200 | 200 | 技术 |
| 2 | alex | female | 48 | 201 | 201 | 人力资源 |
| 3 | wupeiqi | male | 38 | 201 | 201 | 人力资源 |
| 4 | yuanhao | female | 28 | 202 | 202 | 销售 |
| 6 | jingliyang | female | 18 | 204 | NULL | NULL |
+----+------------+--------+------+--------+------+--------------+
6 rows in set (0.00 sec)
mysql> select * from employee right join department on employee.dep_id = department.id ;
+------+-----------+--------+------+--------+------+--------------+
| id | name | sex | age | dep_id | id | name |
+------+-----------+--------+------+--------+------+--------------+
| 1 | egon | male | 18 | 200 | 200 | 技术 |
| 2 | alex | female | 48 | 201 | 201 | 人力资源 |
| 3 | wupeiqi | male | 38 | 201 | 201 | 人力资源 |
| 4 | yuanhao | female | 28 | 202 | 202 | 销售 |
| 5 | liwenzhou | male | 18 | 200 | 200 | 技术 |
| NULL | NULL | NULL | NULL | NULL | 203 | 运营 |
+------+-----------+--------+------+--------+------+--------------+
6 rows in set (0.00 sec)
mysql> select * from employee left join department on employee.dep_id = department.id
-> union
-> select * from employee right join department on employee.dep_id = department.id;
+------+------------+--------+------+--------+------+--------------+
| id | name | sex | age | dep_id | id | name |
+------+------------+--------+------+--------+------+--------------+
| 1 | egon | male | 18 | 200 | 200 | 技术 |
| 5 | liwenzhou | male | 18 | 200 | 200 | 技术 |
| 2 | alex | female | 48 | 201 | 201 | 人力资源 |
| 3 | wupeiqi | male | 38 | 201 | 201 | 人力资源 |
| 4 | yuanhao | female | 28 | 202 | 202 | 销售 |
| 6 | jingliyang | female | 18 | 204 | NULL | NULL |
| NULL | NULL | NULL | NULL | NULL | 203 | 运营 |
+------+------------+--------+------+--------+------+--------------+
7 rows in set (0.11 sec)
#查询平均年龄大于30岁的部门名
select * from employee inner join department on employee.dep_id = department.id;
select department.name,avg(age) from employee inner join department on employee.dep_id = department.id
group by department.name
having avg(age) > 30;
mysql> desc employee;
+--------+-----------------------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+--------+-----------------------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| name | varchar(20) | YES | | NULL | |
| sex | enum(‘male‘,‘female‘) | NO | | male | |
| age | int(11) | YES | | NULL | |
| dep_id | int(11) | YES | | NULL | |
+--------+-----------------------+------+-----+---------+----------------+
5 rows in set (0.01 sec)
mysql> desc department;
+-------+-------------+------+-----+---------+-------+
| Field | Type | Null | Key | Default | Extra |
+-------+-------------+------+-----+---------+-------+
| id | int(11) | YES | | NULL | |
| name | varchar(20) | YES | | NULL | |
+-------+-------------+------+-----+---------+-------+
2 rows in set (0.01 sec)
mysql> select department.name,avg(age) from employee inner join department on employee.dep_id = depa
rtment.id;
ERROR 1140 (42000): Mixing of GROUP columns (MIN(),MAX(),COUNT(),...) with no GROUP columns is illeg
al if there is no GROUP BY clause
mysql> select * from employee inner join department on employee.dep_id = department.id;
+----+-----------+--------+------+--------+------+--------------+
| id | name | sex | age | dep_id | id | name |
+----+-----------+--------+------+--------+------+--------------+
| 1 | egon | male | 18 | 200 | 200 | 技术 |
| 2 | alex | female | 48 | 201 | 201 | 人力资源 |
| 3 | wupeiqi | male | 38 | 201 | 201 | 人力资源 |
| 4 | yuanhao | female | 28 | 202 | 202 | 销售 |
| 5 | liwenzhou | male | 18 | 200 | 200 | 技术 |
+----+-----------+--------+------+--------+------+--------------+
5 rows in set (0.00 sec)
mysql> select department.name,avg(age) from employee inner join department on employee.dep_id = depa
rtment.id
-> group by department.name
-> having avg(age) > 30;
+--------------+----------+
| name | avg(age) |
+--------------+----------+
| 人力资源 | 43.0000 |
+--------------+----------+
1 row in set (0.00 sec)
SELECT语句关键字执行优先级
http://www.cnblogs.com/linhaifeng/articles/7372774.html
子查询
http://www.cnblogs.com/linhaifeng/articles/7267596.html
#1：子查询是将一个查询语句嵌套在另一个查询语句中。 #2：内层查询语句的查询结果，可以为外层查询语句提供查询条件。 #3：子查询中可以包含：IN、NOT IN、ANY、ALL、EXISTS 和 NOT EXISTS等关键字 #4：还可以包含比较运算符：= 、 !=、> 、<等
1、带IN关键字的子查询
查询平均年龄在25岁以上的部门名
select dep_id from employee
group by dep_id
having avg(age) > 25;
mysql> select * from employee;
+----+------------+--------+------+--------+
| id | name | sex | age | dep_id |
+----+------------+--------+------+--------+
| 1 | egon | male | 18 | 200 |
| 2 | alex | female | 48 | 201 |
| 3 | wupeiqi | male | 38 | 201 |
| 4 | yuanhao | female | 28 | 202 |
| 5 | liwenzhou | male | 18 | 200 |
| 6 | jingliyang | female | 18 | 204 |
+----+------------+--------+------+--------+
6 rows in set (0.00 sec)
mysql> select dep_id from employee
-> group by dep_id
-> having avg(age) > 25;
+--------+
| dep_id |
+--------+
| 201 |
| 202 |
+--------+
2 rows in set (0.00 sec)
mysql> select * from department;
+------+--------------+
| id | name |
+------+--------------+
| 200 | 技术 |
| 201 | 人力资源 |
| 202 | 销售 |
| 203 | 运营 |
+------+--------------+
4 rows in set (0.00 sec)
mysql> select name from department where id in
-> (select dep_id from employee
-> group by dep_id
-> having avg(age) > 25);
+--------------+
| name |
+--------------+
| 人力资源 |
| 销售 |
+--------------+
2 rows in set (0.11 sec)
查看技术部员工姓名 #两种表
select * from employee where dep_id = (
select id from department where name = "技术");
查看不足1人（not >=1）的部门名
select name from department where id not in (
select distinct dep_id from employee);
mysql> select id from department where name = "技术";
+------+
| id |
+------+
| 200 |
+------+
1 row in set (0.00 sec)
mysql> select * from employee where dep_id = (
->
-> select id from department where name = "技术");
+----+-----------+------+------+--------+
| id | name | sex | age | dep_id |
+----+-----------+------+------+--------+
| 1 | egon | male | 18 | 200 |
| 5 | liwenzhou | male | 18 | 200 |
+----+-----------+------+------+--------+
2 rows in set (0.00 sec)
mysql> select name from employee where dep_id = (
-> select id from department where name = "技术");
+-----------+
| name |
+-----------+
| egon |
| liwenzhou |
+-----------+
2 rows in set (0.00 sec)
mysql>
mysql>
mysql> select * from employee;
+----+------------+--------+------+--------+
| id | name | sex | age | dep_id |
+----+------------+--------+------+--------+
| 1 | egon | male | 18 | 200 |
| 2 | alex | female | 48 | 201 |
| 3 | wupeiqi | male | 38 | 201 |
| 4 | yuanhao | female | 28 | 202 |
| 5 | liwenzhou | male | 18 | 200 |
| 6 | jingliyang | female | 18 | 204 |
+----+------------+--------+------+--------+
6 rows in set (0.00 sec)
mysql> select dep_id from employee;
+--------+
| dep_id |
+--------+
| 200 |
| 201 |
| 201 |
| 202 |
| 200 |
| 204 |
+--------+
6 rows in set (0.00 sec)
mysql> select distinct dep_id from employee;
+--------+
| dep_id |
+--------+
| 200 |
| 201 |
| 202 |
| 204 |
+--------+
4 rows in set (0.00 sec)
mysql> select name from department where id not in (
-> select distinct dep_id from employee);
+--------+
| name |
+--------+
| 运营 |
+--------+
1 row in set (0.00 sec)
mysql> select * from employee;
+----+------------+--------+------+--------+
| id | name | sex | age | dep_id |
+----+------------+--------+------+--------+
| 1 | egon | male | 18 | 200 |
| 2 | alex | female | 48 | 201 |
| 3 | wupeiqi | male | 38 | 201 |
| 4 | yuanhao | female | 28 | 202 |
| 5 | liwenzhou | male | 18 | 200 |
| 6 | jingliyang | female | 18 | 204 |
+----+------------+--------+------+--------+
6 rows in set (0.00 sec)
mysql> select * from department;
+------+--------------+
| id | name |
+------+--------------+
| 200 | 技术 |
| 201 | 人力资源 |
| 202 | 销售 |
| 203 | 运营 |
+------+--------------+
4 rows in set (0.00 sec)
2、带比较运算符的子查询
查询大于所有人平均年龄的员工名与年龄 #先拿到所有人的平均年龄，然后把它作为条件
select name,age from employee where age > (select avg(age) from employee);
mysql> select avg(age) from employee; +----------+ | avg(age) | +----------+ | 28.0000 | +----------+ 1 row in set (0.06 sec) mysql> select name,age from employee where age > (select avg(age) from employee); +---------+------+ | name | age | +---------+------+ | alex | 48 | | wupeiqi | 38 | +---------+------+ 2 rows in set (0.00 sec)
3、带EXISTS关键字的子查询 #针对某一个子查询问一问它有没有结果，有就为真了；
条件成立就拿到了
select * from employee
where EXISTS
(select id from department where name = "技术");
mysql> select * from employee
-> where EXISTS
-> (select id from department where name = "技术");
+----+------------+--------+------+--------+
| id | name | sex | age | dep_id |
+----+------------+--------+------+--------+
| 1 | egon | male | 18 | 200 |
| 2 | alex | female | 48 | 201 |
| 3 | wupeiqi | male | 38 | 201 |
| 4 | yuanhao | female | 28 | 202 |
| 5 | liwenzhou | male | 18 | 200 |
| 6 | jingliyang | female | 18 | 204 |
+----+------------+--------+------+--------+
6 rows in set (0.00 sec)
->
-> \c
mysql> select * from employee
-> where EXISTS
-> (select id from department where name = "IT");
Empty set (0.00 sec)
把在内存中虚拟表留下来以便你查询用，把查询表起个名字当做一个表来用；
mysql> select id,name,sex from employee;
+----+------------+--------+
| id | name | sex |
+----+------------+--------+
| 1 | egon | male |
| 2 | alex | female |
| 3 | wupeiqi | male |
| 4 | yuanhao | female |
| 5 | liwenzhou | male |
| 6 | jingliyang | female |
+----+------------+--------+
6 rows in set (0.00 sec)
mysql> select * from
-> (select id,name,sex from employee)as t1;
+----+------------+--------+
| id | name | sex |
+----+------------+--------+
| 1 | egon | male |
| 2 | alex | female |
| 3 | wupeiqi | male |
| 4 | yuanhao | female |
| 5 | liwenzhou | male |
| 6 | jingliyang | female |
+----+------------+--------+
6 rows in set (0.09 sec)
#统计每个（分组，得到聚合的结果）部门最新（时间最大的一个）入职的员工
select post ,max(hire_date) from employee group by post;
得到的新表和原表连接到一起了
mysql> use db5;
Database changed
mysql> show tables;
+---------------+
| Tables_in_db5 |
+---------------+
| customer |
| employee |
| student |
+---------------+
3 rows in set (0.10 sec)
mysql> select * from employee;
+----+------------+--------+-----+------------+-----------------------------------------+--------------+------------+--------+-----------+
| id | name | sex | age | hire_date | post | post_comment | salary | office | depart_id |
+----+------------+--------+-----+------------+-----------------------------------------+--------------+------------+--------+-----------+
| 1 | egon | male | 18 | 2017-03-01 | 老男孩驻沙河办事处外交大使 | NULL | 7300.33 | 401 | 1 |
| 2 | alex | male | 78 | 2015-03-02 | teacher | NULL | 1000000.31 | 401 | 1 |
| 3 | wupeiqi | male | 81 | 2013-03-05 | teacher | NULL | 8300.00 | 401 | 1 |
| 4 | yuanhao | male | 73 | 2014-07-01 | teacher | NULL | 3500.00 | 401 | 1 |
| 5 | liwenzhou | male | 28 | 2012-11-01 | teacher | NULL | 2100.00 | 401 | 1 |
| 6 | jingliyang | female | 18 | 2011-02-11 | teacher | NULL | 9000.00 | 401 | 1 |
| 7 | jinxin | male | 18 | 1900-03-01 | teacher | NULL | 30000.00 | 401 | 1 |
| 8 | 成龙 | male | 48 | 2010-11-11 | teacher | NULL | 10000.00 | 401 | 1 |
| 9 | 歪歪 | female | 48 | 2015-03-11 | sale | NULL | 3000.13 | 402 | 2 |
| 10 | 丫丫 | female | 38 | 2010-11-01 | sale | NULL | 2000.35 | 402 | 2 |
| 11 | 丁丁 | female | 18 | 2011-03-12 | sale | NULL | 1000.37 | 402 | 2 |
| 12 | 星星 | female | 18 | 2016-05-13 | sale | NULL | 3000.29 | 402 | 2 |
| 13 | 格格 | female | 28 | 2017-01-27 | sale | NULL | 4000.33 | 402 | 2 |
| 14 | 张野 | male | 28 | 2016-03-11 | operation | NULL | 10000.13 | 403 | 3 |
| 15 | 程咬金 | male | 18 | 1997-03-12 | operation | NULL | 20000.00 | 403 | 3 |
| 16 | 程咬银 | female | 18 | 2013-03-11 | operation | NULL | 19000.00 | 403 | 3 |
| 17 | 程咬铜 | male | 18 | 2015-04-11 | operation | NULL | 18000.00 | 403 | 3 |
| 18 | 程咬铁 | female | 18 | 2014-05-12 | operation | NULL | 17000.00 | 403 | 3 |
+----+------------+--------+-----+------------+-----------------------------------------+--------------+------------+--------+-----------+
18 rows in set (0.00 sec)
mysql> select post ,max(hire_date) from employee group by post;
+-----------------------------------------+----------------+
| post | max(hire_date) |
+-----------------------------------------+----------------+
| operation | 2016-03-11 |
| sale | 2017-01-27 |
| teacher | 2015-03-02 |
| 老男孩驻沙河办事处外交大使 | 2017-03-01 |
+-----------------------------------------+----------------+
4 rows in set (0.06 sec)
mysql> select * from employee as t1
-> inner join
-> (select post ,max(hire_date) from employee group by post) as t2
-> on t1.post = t2.post;
+----+------------+--------+-----+------------+-----------------------------------------+--------------+------------+--------+-----------+-----------------------------------------+----------------+
| id | name | sex | age | hire_date | post | post_comment | salary | office | depart_id | post | max(hire_date) |
+----+------------+--------+-----+------------+-----------------------------------------+--------------+------------+--------+-----------+-----------------------------------------+----------------+
| 1 | egon | male | 18 | 2017-03-01 | 老男孩驻沙河办事处外交大使 | NULL | 7300.33 | 401 | 1 | 老男孩驻沙河办事处外交大使 | 2017-03-01 |
| 2 | alex | male | 78 | 2015-03-02 | teacher | NULL | 1000000.31 | 401 | 1 | teacher | 2015-03-02 |
| 3 | wupeiqi | male | 81 | 2013-03-05 | teacher | NULL | 8300.00 | 401 | 1 | teacher | 2015-03-02 |
| 4 | yuanhao | male | 73 | 2014-07-01 | teacher | NULL | 3500.00 | 401 | 1 | teacher | 2015-03-02 |
| 5 | liwenzhou | male | 28 | 2012-11-01 | teacher | NULL | 2100.00 | 401 | 1 | teacher | 2015-03-02 |
| 6 | jingliyang | female | 18 | 2011-02-11 | teacher | NULL | 9000.00 | 401 | 1 | teacher | 2015-03-02 |
| 7 | jinxin | male | 18 | 1900-03-01 | teacher | NULL | 30000.00 | 401 | 1 | teacher | 2015-03-02 |
| 8 | 成龙 | male | 48 | 2010-11-11 | teacher | NULL | 10000.00 | 401 | 1 | teacher | 2015-03-02 |
| 9 | 歪歪 | female | 48 | 2015-03-11 | sale | NULL | 3000.13 | 402 | 2 | sale | 2017-01-27 |
| 10 | 丫丫 | female | 38 | 2010-11-01 | sale | NULL | 2000.35 | 402 | 2 | sale | 2017-01-27 |
| 11 | 丁丁 | female | 18 | 2011-03-12 | sale | NULL | 1000.37 | 402 | 2 | sale | 2017-01-27 |
| 12 | 星星 | female | 18 | 2016-05-13 | sale | NULL | 3000.29 | 402 | 2 | sale | 2017-01-27 |
| 13 | 格格 | female | 28 | 2017-01-27 | sale | NULL | 4000.33 | 402 | 2 | sale | 2017-01-27 |
| 14 | 张野 | male | 28 | 2016-03-11 | operation | NULL | 10000.13 | 403 | 3 | operation | 2016-03-11 |
| 15 | 程咬金 | male | 18 | 1997-03-12 | operation | NULL | 20000.00 | 403 | 3 | operation | 2016-03-11 |
| 16 | 程咬银 | female | 18 | 2013-03-11 | operation | NULL | 19000.00 | 403 | 3 | operation | 2016-03-11 |
| 17 | 程咬铜 | male | 18 | 2015-04-11 | operation | NULL | 18000.00 | 403 | 3 | operation | 2016-03-11 |
| 18 | 程咬铁 | female | 18 | 2014-05-12 | operation | NULL | 17000.00 | 403 | 3 | operation | 2016-03-11 |
+----+------------+--------+-----+------------+-----------------------------------------+--------------+------------+--------+-----------+-----------------------------------------+----------------+
18 rows in set (0.00 sec)
mysql> select post ,max(hire_date) from employee group by post;
+-----------------------------------------+----------------+
| post | max(hire_date) |
+-----------------------------------------+----------------+
| operation | 2016-03-11 |
| sale | 2017-01-27 |
| teacher | 2015-03-02 |
| 老男孩驻沙河办事处外交大使 | 2017-03-01 |
+-----------------------------------------+----------------+
4 rows in set (0.04 sec)
mysql> select * from employee as t1
-> inner join
-> (select post ,max(hire_date) as max_hire_date from employee group by post) as t2
-> on t1.post = t2.post
-> where t1.hire_date = t2.max_hire_date;
+----+--------+--------+-----+------------+-----------------------------------------+--------------+------------+--------+-----------+-----------------------------------------+---------------+
| id | name | sex | age | hire_date | post | post_comment | salary | office | depart_id | post | max_hire_date |
+----+--------+--------+-----+------------+-----------------------------------------+--------------+------------+--------+-----------+-----------------------------------------+---------------+
| 1 | egon | male | 18 | 2017-03-01 | 老男孩驻沙河办事处外交大使 | NULL | 7300.33 | 401 | 1 | 老男孩驻沙河办事处外交大使 | 2017-03-01 |
| 2 | alex | male | 78 | 2015-03-02 | teacher | NULL | 1000000.31 | 401 | 1 | teacher | 2015-03-02 |
| 13 | 格格 | female | 28 | 2017-01-27 | sale | NULL | 4000.33 | 402 | 2 | sale | 2017-01-27 |
| 14 | 张野 | male | 28 | 2016-03-11 | operation | NULL | 10000.13 | 403 | 3 | operation | 2016-03-11 |
+----+--------+--------+-----+------------+-----------------------------------------+--------------+------------+--------+-----------+-----------------------------------------+---------------+
4 rows in set (0.07 sec)
权限管理
权限管理
1、创建账号
# 本地账号
create user ‘egon1‘@‘localhost‘ identified by ‘123‘; # mysql -uegon1 -p123
# 远程帐号 #前提是31.10能拼通我服务端的ip这才有意义
create user ‘egon2‘@‘192.168.31.10‘ identified by ‘123‘; # mysql -uegon2 -p123 -h 指定的是服务端ip ##运行egon2在这台机器之上登录；‘192.168.31.10’是客户端的ip地址
create user ‘egon3‘@‘192.168.31.%‘ identified by ‘123‘; # mysql -uegon3 -p123 -h 服务端ip #表示egon3用户能在31这段网中任意登录
create user ‘egon3‘@‘%‘ identified by ‘123‘; # mysql -uegon3 -p123 -h 服务端ip #所有的客户端ip都能登录，只要你能拼通服务端。
2、授权 这几张表对权限的控制是依次降低的
user:*.* # *.* 所有库下边所有的表 只要user一放权，下面所有的都可以用了
db:db1.* #具体写哪个库，只对某个库有查询权限，库下边所有的表
tables_priv:db1.t1 #表级别的权限
columns_priv:id,name #针对某个字段
grant all on *.* to ‘egon1‘@‘localhost‘; #授权多有的权限，*.*是user下所有级别的；
grant select on *.* to ‘egon1‘@‘localhost‘;
revoke select on *.* from ‘egon1‘@‘localhost‘; #回收权限
grant select on db1.* to ‘egon1‘@‘localhost‘;
revoke select on db1.* from ‘egon1‘@‘localhost‘;
grant select on db1.t1 to ‘kris1‘@‘localhost‘;# -uroot 只放行了对t1的权限 #先查看下 select * from mysql.user\G 看select权限有没有看；再看select * from mysql.db\G 查看下select权限有没开 #select * from mysql.tables_priv\G ,看到有权限了；验证下：exit mysql -ukris1 -p123 -->> show databeses; -->use db1; -->show tables;->select * from t1;
revoke select on db1.t2 from ‘egon1‘@‘localhost‘;
grant select(id,name),update(age) on db1.t2 to ‘egon1‘@‘localhost‘; #精确到字段级别 #select * from mysql.columns_priv;
mysql> create user ‘kris1‘@‘localhost‘ identified by ‘123‘;
Query OK, 0 rows affected (0.39 sec)
mysql> select * from mysql.user\G
*************************** 1. row ***************************
Host: localhost
User: root
Password:
Select_priv: Y
Insert_priv: Y
Update_priv: Y
Delete_priv: Y
.....
max_connections: 0
max_user_connections: 0
plugin: mysql_native_password
authentication_string:
password_expired: N
*************************** 2. row ***************************
Host: 127.0.0.1
User: root
Password:
Select_priv: Y
Insert_priv: Y
Update_priv: Y
Del......
authentication_string:
password_expired: N
*************************** 3. row ***************************
Host: ::1
User: root
Password:
Select_priv: Y
Insert_priv: Y
Update_priv: Y
......
password_expired: N
*************************** 4. row ***************************
Host: localhost
User:
Password:
Select_priv: N
I.........*************************** 5. row ***************************
Host: localhost
User: kris1
Password: *23AE809DDACAF96AF0FD78ED04B6A265E05AA257
Select_priv: N #下面的都有N，造出来的权限默认是在user表里边，user没有放行任何权限，但不一定这个用户一定就没有权限；
Insert_priv: N
Update_priv: N
Delete_priv: N
Create_priv: N
Drop_priv: N
Reload_priv: N
Shutdown_priv: N
Process_priv: N
File_priv: N
Grant_priv: N
References_priv: N
Index_priv: N
Alter_priv: N
Show_db_priv: N
Super_priv: N
Create_tmp_table_priv: N
Lock_tables_priv: N
Execute_priv: N
Repl_slave_priv: N
Repl_client_priv: N
Create_view_priv: N
Show_view_priv: N
Create_routine_priv: N
Alter_routine_priv: N
Create_user_priv: N
Event_priv: N
Trigger_priv: N
Create_tablespace_priv: N
ssl_type:
ssl_cipher:
x509_issuer:
x509_subject:
max_questions: 0
max_updates: 0
max_connections: 0
max_user_connections: 0
plugin: mysql_native_password
authentication_string:
password_expired: N
5 rows in set (0.05 sec)
mysql> select * from mysql.db\G #查看下面的db表
*************************** 1. row ***************************
Host: % ##有关于库相关的权限，但没有具体到用户，用户都是空的，意味着对任何用户都是有效的，包括刚刚的kris1；%代表任意的，包含localhost
Db: test
User:
Select_priv: Y
Insert_priv: Y
Update_priv: Y
Delete_priv: Y
Create_priv: Y
Drop_priv: Y
Grant_priv: N
References_priv: Y
Index_priv: Y
Alter_priv: Y
Create_tmp_table_priv: Y
Lock_tables_priv: Y
Create_view_priv: Y
Show_view_priv: Y
Create_routine_priv: Y
Alter_routine_priv: N
Execute_priv: N
Event_priv: Y
Trigger_priv: Y
*************************** 2. row ***************************
Host: %
Db: test\_% #对db下的以 __开头的任意都有权限
User:
Select_priv: Y
Insert_priv: Y
Update_priv: Y
Delete_priv: Y
Create_priv: Y
Drop_priv: Y
Grant_priv: N
References_priv: Y
Index_priv: Y
Alter_priv: Y
Create_tmp_table_priv: Y
Lock_tables_priv: Y
Create_view_priv: Y
Show_view_priv: Y
Create_routine_priv: Y
Alter_routine_priv: N
Execute_priv: N
Event_priv: Y
Trigger_priv: Y
2 rows in set (0.00 sec)
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| db1 |
| db2 |
| db3 |
| db4 |
| db5 |
| db6 |
| mysql |
| performance_schema |
| test |
+--------------------+
10 rows in set (0.68 sec)
mysql> create database test_1;
Query OK, 1 row affected (0.06 sec)
mysql> create database test2;
Query OK, 1 row affected (0.03 sec)
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| db1 |
| db2 |
| db3 |
| db4 |
| db5 |
| db6 |
| mysql |
| performance_schema |
| test |
| test2 |
| test_1 |
+--------------------+
12 rows in set (0.00 sec)
mysql> exit
Bye
C:\Users\Administrator>mysql -ukris1 -p123
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 8
Server version: 5.6.39 MySQL Community Server (GPL)
Copyright (c) 2000, 2018, 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> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| test |
| test_1 |
+--------------------+
3 rows in set (0.00 sec)
mysql> drop database test_1;
Query OK, 0 rows affected (0.64 sec)
mysql> use test;
Database changed
mysql> show tables;
Empty set (0.06 sec)
C:\Users\Administrator>mysql -uroot -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 9
Server version: 5.6.39 MySQL Community Server (GPL)
Copyright (c) 2000, 2018, 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 select on *.* to ‘kris1‘@‘localhost‘;
Query OK, 0 rows affected (0.01 sec)
mysql> select * from mysql.user\G
*************************** 1. row ***************************
Host: localhost
User: root
Password:
Select_priv: Y
Insert_priv: Y
Update_priv: Y
Delete_priv: Y
Create_priv: Y
Drop_priv: Y
Reload_priv: Y
Shutdown_priv: Y
Process_priv: Y
File_priv: Y
Grant_priv: Y
References_priv: Y
Index_priv: Y
Alter_priv: Y
Show_db_priv: Y
Super_priv: Y
Create_tmp_table_priv: Y
Lock_tables_priv: Y
Execute_priv: Y
Repl_slave_priv: Y
Repl_client_priv: Y
Create_view_priv: Y
Show_view_priv: Y
Create_routine_priv: Y
Alter_routine_priv: Y
Create_user_priv: Y
Event_priv: Y
Trigger_priv: Y
Create_tablespace_priv: Y
ssl_type:
ssl_cipher:
x509_issuer:
x509_subject:
max_questions: 0
max_updates: 0
max_connections: 0
max_user_connections: 0
plugin: mysql_native_password
authentication_string:
password_expired: N
*************************** 2. row ***************************
Host: 127.0.0.1
User: root
Password:
Select_priv: Y
Insert_priv: Y
*************************** 3. row ***************************
Host: ::1
User: root
Password:
Select_priv: Y
......
password_expired: N
*************************** 4. row ***************************
Host: localhost
User:
Password:
Select_priv: N
Insert_priv: N
Update_priv: N
.....
Create_tablespace_priv: N
ssl_type:
.....*************************** 5. row ***************************
Host: localhost
User: kris1
Password: *23AE809DDACAF96AF0FD78ED04B6A265E05AA257
Select_priv: Y
Insert_priv: N
Update_priv: N
Delete_priv: N
Create_priv: N
Drop_priv: N
Reload_priv: N
Shutdown_priv: N
Process_priv: N
File_priv: N
Grant_priv: N
References_priv: N
Index_priv: N
Alter_priv: N
Show_db_priv: N
Super_priv: N
Create_tmp_table_priv: N
Lock_tables_priv: N
Execute_priv: N
Repl_slave_priv: N
Repl_client_priv: N
Create_view_priv: N
Show_view_priv: N
Create_routine_priv: N
Alter_routine_priv: N
Create_user_priv: N
Event_priv: N
Trigger_priv: N
Create_tablespace_priv: N
ssl_type:
ssl_cipher:
x509_issuer:
x509_subject:
max_questions: 0
max_updates: 0
max_connections: 0
max_user_connections: 0
plugin: mysql_native_password
authentication_string:
password_expired: N
5 rows in set (0.05 sec)
mysql> exit
Bye
C:\Users\Administrator>mysql -ukris1 -p123
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 10
Server version: 5.6.39 MySQL Community Server (GPL)
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| db1 |
| db2 |
| db3 |
| db4 |
| db5 |
| db6 |
| mysql |
| performance_schema |
| test |
| test2 |
+--------------------+
11 rows in set (0.05 sec)
mysql> use db1;
Database changed
mysql> show tables;
+---------------+
| Tables_in_db1 |
+---------------+
| t1 |
+---------------+
1 row in set (0.00 sec)
mysql> select * from t1;
+------+------+
| id | name |
+------+------+
| 1 | SB |
| 3 | SB |
+------+------+
2 rows in set (0.24 sec)
mysql> insert into t2 values(4, ‘kris1‘,45);
ERROR 1142 (42000): INSERT command denied to user ‘kris1‘@‘localhost‘ for table ‘t2‘
mysql>
C:\Users\Administrator>mysql -uroot -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 11
Server version: 5.6.39 MySQL Community Server (GPL)
Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights r
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
mysql> revoke select on *.* from ‘kris1‘@‘localhost‘;
Query OK, 0 rows affected (0.00 sec)
mysql> select * from mysql.user\G
*************************** 1. row ***************************
......
*************************** 5. row ***************************
Host: localhost
User: kris1
Password: *23AE809DDACAF96AF0FD78ED04B6A265E05AA257
Select_priv: N #又没有权限了
Insert_priv: N
Update_priv: N
Delete_priv: N
Create_priv: N
Drop_priv: N
Reload_priv: N
Shutdown_priv: N
Process_priv: N
File_priv: N
Grant_priv: N
References_priv: N
Index_priv: N
Alter_priv: N
Show_db_priv: N
Super_priv: N
Create_tmp_table_priv: N
Lock_tables_priv: N
Execute_priv: N
Repl_slave_priv: N
Repl_client_priv: N
Create_view_priv: N
Show_view_priv: N
Create_routine_priv: N
Alter_routine_priv: N
Create_user_priv: N
Event_priv: N
Trigger_priv: N
Create_tablespace_priv: N
ssl_type:
ssl_cipher:
x509_issuer:
x509_subject:
max_questions: 0
max_updates: 0
max_connections: 0
max_user_connections: 0
plugin: mysql_native_password
authentication_string:
password_expired: N
5 rows in set (0.00 sec)
mysql> grant select on db1.* to ‘kris1‘@‘localhost‘;
Query OK, 0 rows affected (0.00 sec)
mysql> select * from mysql.db\G
*************************** 1. row ***************************
Host: %
Db: test
User:
Select_priv: Y
Insert_priv: Y
Update_priv: Y
Delete_priv: Y
Create_priv: Y
Drop_priv: Y
Grant_priv: N
References_priv: Y
Index_priv: Y
Alter_priv: Y
Create_tmp_table_priv: Y
Lock_tables_priv: Y
Create_view_priv: Y
Show_view_priv: Y
Create_routine_priv: Y
Alter_routine_priv: N
Execute_priv: N
Event_priv: Y
Trigger_priv: Y
*************************** 2. row ***************************
Host: %
Db: test\_%
User:
Select_priv: Y
Insert_priv: Y
Update_priv: Y
Delete_priv: Y
Create_priv: Y
Drop_priv: Y
Grant_priv: N
References_priv: Y
Index_priv: Y
Alter_priv: Y
Create_tmp_table_priv: Y
Lock_tables_priv: Y
Create_view_priv: Y
Show_view_priv: Y
Create_routine_priv: Y
Alter_routine_priv: N
Execute_priv: N
Event_priv: Y
Trigger_priv: Y
*************************** 3. row ***************************
Host: localhost
Db: db1
User: kris1
Select_priv: Y
Insert_priv: N
Update_priv: N
Delete_priv: N
Create_priv: N
Drop_priv: N
Grant_priv: N
References_priv: N
Index_priv: N
Alter_priv: N
Create_tmp_table_priv: N
Lock_tables_priv: N
Create_view_priv: N
Show_view_priv: N
Create_routine_priv: N
Alter_routine_priv: N
Execute_priv: N
Event_priv: N
Trigger_priv: N
3 rows in set (0.00 sec)
mysql> exit
Bye
C:\Users\Administrator>mysql -ukris1 -p123
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 12
Server version: 5.6.39 MySQL Community Server (GPL)
Copyright (c) 2000, 2018, 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> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| db1 |
| test |
+--------------------+
3 rows in set (0.00 sec)
mysql> use db1;
Database changed
mysql> show tables;
+---------------+
| Tables_in_db1 |
+---------------+
| t1 |
+---------------+
1 row in set (0.00 sec)
mysql> select * from t1;
+------+------+
| id | name |
+------+------+
| 1 | SB |
| 3 | SB |
+------+------+
2 rows in set (0.00 sec)
mysql> insert into t1 values(2,‘SB‘);
ERROR 1142 (42000): INSERT command denied to user ‘kris1‘@‘localhost‘ for table ‘t
mysql> exit
Bye
C:\Users\Administrator>mysql -uroot -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 13
Server version: 5.6.39 MySQL Community Server (GPL)
Copyright (c) 2000, 2018, 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> revoke select on db1.* from ‘kris1‘@‘localhost‘;
Query OK, 0 rows affected (0.00 sec)
原文地址：https://www.cnblogs.com/shengyang17/p/8961848.html
时间： 2024-11-07 12:04:44