MySQL中的排名功能教程
我需要找出客户的排名.在这里,我为我的要求添加了相应的ANSI标准SQL查询.请帮我转换为MySQL.
SELECT RANK() OVER (PARTITION BY Gender ORDER BY Age) AS [Partition by Gender],
FirstName,
Age,
Gender
FROM Person
有没有找到MySQL排名的函数?
解决方法:
一种选择是使用排名变量,例如:
SELECT first_name,
age,
gender,
@curRank := @curRank + 1 AS rank
FROM person p, (SELECT @curRank := 0) r
ORDER BY age;
(SELECT @curRank:= 0)部分允许变量初始化而无需单独的SET命令.
测试用例:
CREATE TABLE person (id int, first_name varchar(20), age int, gender char(1));
INSERT INTO person VALUES (1, 'Bob', 25, 'M');
INSERT INTO person VALUES (2, 'Jane', 20, 'F');
INSERT INTO person VALUES (3, 'Jack', 30, 'M');
INSERT INTO person VALUES (4, 'Bill', 32, 'M');
INSERT INTO person VALUES (5, 'Nick', 22, 'M');
INSERT INTO person VALUES (6, 'Kathy', 18, 'F');
INSERT INTO person VALUES (7, 'Steve', 36, 'M');
INSERT INTO person VALUES (8, 'Anne', 25, 'F');
结果:
+------------+------+--------+------+
| first_name | age | gender | rank |
+------------+------+--------+------+
| Kathy | 18 | F | 1 |
| Jane | 20 | F | 2 |
| Nick | 22 | M | 3 |
| Bob | 25 | M | 4 |
| Anne | 25 | F | 5 |
| Jack | 30 | M | 6 |
| Bill | 32 | M | 7 |
| Steve | 36 | M | 8 |
+------------+------+--------+------+
8 rows in set (0.02 sec)