MySQL学习，详解排序查询（order by）

排序查询（order by）

电商中：我们想查看今天所有成交的订单，按照交易额从⾼到低排序，此时我们可以使⽤

数据库中的排序功能来完成。

排序语法：

select 字段名 from 表名 order by 字段1 [asc|desc],字段2 [asc|desc];

需要排序的字段跟在order by之后；

asc|desc表⽰排序的规则，asc：升序，desc：降序，默认为asc；

⽀持多个字段进⾏排序，多字段排序之间⽤逗号隔开。

这是Mysql系列第8篇。

环境：mysql5.7.25，cmd命令中进⾏演⽰。

代码中被[]包含的表⽰可选，|符号分开的表⽰可选其⼀。单字段排序

mysql> create table test2(a int,b varchar(10));

Query OK, 0 rows affected (0.01 sec)

mysql> insert into test2 values (10,'jack'),(8,'tom'),(5,'ready'),

(100,'javacode');

Query OK, 4 rows affected (0.00 sec)

Records: 4 Duplicates: 0 Warnings: 0

mysql> select * from test2;

+------+----------+

| a | b |

+------+----------+

| 10 | jack |

| 8 | tom |

| 5 | ready |

| 100 | javacode |

+------+----------+

4 rows in set (0.00 sec)

mysql> select * from test2 order by a asc;

+------+----------+

| a | b |

+------+----------+

| 5 | ready |

| 8 | tom |

| 10 | jack |

| 100 | javacode |

+------+----------+

4 rows in set (0.00 sec)

mysql> select * from test2 order by a desc;

+------+----------+

| a | b |

+------+----------+

| 100 | javacode |

| 10 | jack |

| 8 | tom |

| 5 | ready |

+------+----------+4 rows in set (0.00 sec)

mysql> select * from test2 order by a;

+------+----------+

| a | b |

+------+----------+

| 5 | ready |

| 8 | tom |

| 10 | jack |

| 100 | javacode |

+------+----------+

4 rows in set (0.00 sec)

多字段排序

⽐如学⽣表，先按学⽣年龄降序，年龄相同时，再按学号升序，如下：

mysql> create table stu(id int not null comment '学号' primary key,age

tinyint not null comment '年龄',name varchar(16) comment '姓名');

Query OK, 0 rows affected (0.01 sec)

mysql> insert into stu (id,age,name) values (1001,18,'路⼈甲Java'),

(1005,20,'刘德华'),(1003,18,'张学友'),(1004,20,'张国荣'),(1010,19,'梁朝

伟');

Query OK, 5 rows affected (0.00 sec)

Records: 5 Duplicates: 0 Warnings: 0

mysql> select * from stu;

+------+-----+---------------+

| id | age | name |

+------+-----+---------------+

| 1001 | 18 | 路⼈甲Java |

| 1003 | 18 | 张学友 |

| 1004 | 20 | 张国荣 |

| 1005 | 20 | 刘德华 |

| 1010 | 19 | 梁朝伟 |

+------+-----+---------------+

5 rows in set (0.00 sec)mysql> select * from stu order by age desc,id asc;

+------+-----+---------------+

| id | age | name |

+------+-----+---------------+

| 1004 | 20 | 张国荣 |

| 1005 | 20 | 刘德华 |

| 1010 | 19 | 梁朝伟 |

| 1001 | 18 | 路⼈甲Java |

| 1003 | 18 | 张学友 |

+------+-----+---------------+

5 rows in set (0.00 sec)

按别名排序

mysql> select * from stu;

+------+-----+---------------+

| id | age | name |

+------+-----+---------------+

| 1001 | 18 | 路⼈甲Java |

| 1003 | 18 | 张学友 |

| 1004 | 20 | 张国荣 |

| 1005 | 20 | 刘德华 |

| 1010 | 19 | 梁朝伟 |

+------+-----+---------------+

5 rows in set (0.00 sec)

mysql> select age '年龄',id as '学号' from stu order by 年龄 asc,学号

desc;

+--------+--------+

| 年龄 | 学号 |

+--------+--------+

| 18 | 1003 |

| 18 | 1001 |

| 19 | 1010 |

| 20 | 1005 |

| 20 | 1004 |

+--------+--------+按函数排序

有学⽣表（id：编号，birth：出⽣⽇期，name：姓名），如下：

mysql> drop table if exists student;

Query OK, 0 rows affected (0.01 sec)

mysql> CREATE TABLE student (

-> id int(11) NOT NULL COMMENT '学号',

-> birth date NOT NULL COMMENT '出⽣⽇期',

-> name varchar(16) DEFAULT NULL COMMENT '姓名',

-> PRIMARY KEY (id)

-> );

Query OK, 0 rows affected (0.01 sec)

mysql> insert into student (id,birth,name) values

(1001,'1990-10-10','路⼈甲Java'),(1005,'1960-03-01','刘德华'),

(1003,'1960-08-16','张学友'),(1004,'1968-07-01','张国荣'),

(1010,'1962-05-16','梁朝伟');

Query OK, 5 rows affected (0.00 sec)

Records: 5 Duplicates: 0 Warnings: 0

mysql>

mysql> SELECT * FROM student;

+------+------------+---------------+

| id | birth | name |

+------+------------+---------------+

| 1001 | 1990-10-10 | 路⼈甲Java |

| 1003 | 1960-08-16 | 张学友 |

| 1004 | 1968-07-01 | 张国荣 |

| 1005 | 1960-03-01 | 刘德华 |

| 1010 | 1962-05-16 | 梁朝伟 |

+------+------------+---------------+

5 rows in set (0.00 sec)

需求：按照出⽣年份升序、编号升序，查询出编号、出⽣⽇期、出⽣年份、姓名，2种写

法如下：mysql> SELECT id 编号,birth 出⽣⽇期,year(birth) 出⽣年份,name 姓名 from

student ORDER BY year(birth) asc,id asc;

+--------+--------------+--------------+---------------+

| 编号 | 出⽣⽇期 | 出⽣年份 | 姓名 |

+--------+--------------+--------------+---------------+

| 1003 | 1960-08-16 | 1960 | 张学友 |

| 1005 | 1960-03-01 | 1960 | 刘德华 |

| 1010 | 1962-05-16 | 1962 | 梁朝伟 |

| 1004 | 1968-07-01 | 1968 | 张国荣 |

| 1001 | 1990-10-10 | 1990 | 路⼈甲Java |

+--------+--------------+--------------+---------------+

5 rows in set (0.00 sec)

mysql> SELECT id 编号,birth 出⽣⽇期,year(birth) 出⽣年份,name 姓名 from

student ORDER BY 出⽣年份 asc,id asc;

+--------+--------------+--------------+---------------+

| 编号 | 出⽣⽇期 | 出⽣年份 | 姓名 |

+--------+--------------+--------------+---------------+

| 1003 | 1960-08-16 | 1960 | 张学友 |

| 1005 | 1960-03-01 | 1960 | 刘德华 |

| 1010 | 1962-05-16 | 1962 | 梁朝伟 |

| 1004 | 1968-07-01 | 1968 | 张国荣 |

| 1001 | 1990-10-10 | 1990 | 路⼈甲Java |

+--------+--------------+--------------+---------------+

5 rows in set (0.00 sec)

说明：

year函数：属于⽇期函数，可以获取对应⽇期中的年份。

上⾯使⽤了2种⽅式排序，第⼀种是在order by中使⽤了函数，第⼆种是使⽤了

别名排序。

where之后进⾏排序

有订单数据如下：mysql> drop table if exists t_order;

Query OK, 0 rows affected, 1 warning (0.00 sec)

mysql> create table t_order(

-> id int not null auto_increment comment '订单编号',

-> price decimal(10,2) not null default 0 comment '订单⾦额',

-> primary key(id)

-> )comment '订单表';

Query OK, 0 rows affected (0.01 sec)

mysql> insert into t_order (price) values (88.95),(100.68),(500),

(300),(20.88),(200.5);

Query OK, 6 rows affected (0.00 sec)

Records: 6 Duplicates: 0 Warnings: 0

mysql> select * from t_order;

+----+--------+

| id | price |

+----+--------+

| 1 | 88.95 |

| 2 | 100.68 |

| 3 | 500.00 |

| 4 | 300.00 |

| 5 | 20.88 |

| 6 | 200.50 |

+----+--------+

6 rows in set (0.00 sec)

需求：查询订单⾦额>=100的，按照订单⾦额降序排序，显⽰2列数据，列头：订单编

号、订单⾦额，如下：

mysql> select a.id 订单编号,a.price 订单⾦额 from t_order a where

a.price>=100 order by a.price desc;

+--------------+--------------+

| 订单编号 | 订单⾦额 |

+--------------+--------------+

| 3 | 500.00 |

| 4 | 300.00 |

| 6 | 200.50 |

| 2 | 100.68 |+--------------+--------------+

4 rows in set (0.00 sec)