Mysql 按年龄分组的sql

希望你能帮助我

我有以下数据库：

country | Date_of_birth
-----------------------
france  | 1980-07-01
spain   | 1978-03-23
greece  | 1981-05-05
germany | 1974-08-11

我试图得到这个结果：

country | 13 - 17 | 25 - 45 | 65 - 75
-------------------------------------
france  |         |     1   |
spain   |         |     1   |
greece  |         |     1   |

到目前为止我发现的问题是：

SELECT SUM( IF( age BETWEEN 13 AND 17 , 1, 0)) AS '13 - 17', 
       SUM( IF( age BETWEEN 25 AND 45 , 1, 0)) AS '25 - 45', 
       SUM( IF( age BETWEEN 65 AND 75 , 1, 0)) AS '65 - 75'
FROM (SELECT TIMESTAMPDIFF( YEAR, Date_of_birth, CURDATE()) AS age, country FROM data
) AS test
GROUP BY country
HAVING country IN ("france","greece,"spain")

结果:

 13 - 17 | 25 - 45 | 65 - 75
----------------------------
         |     1   |
         |     1   |
         |     1   |

你知道我一开始是怎么得到“国家”专栏的吗

---

提前谢谢

仅对聚合列起作用。您需要一个简单的
，其中
：

SELECT 
       country,
       SUM(age BETWEEN 13 AND 17) AS '13 - 17', 
       SUM(age BETWEEN 25 AND 45) AS '25 - 45', 
       SUM(age BETWEEN 65 AND 75) AS '65 - 75'
FROM (SELECT TIMESTAMPDIFF( YEAR, Date_of_birth, CURDATE()) AS age, country FROM data
      ) AS test
WHERE country IN ('france', 'greece', 'spain')
GROUP BY country

还要注意查询的简化：在mysql中，
true
是
1
，
false
是
0
，因此您可以简单地对条件求和-您不需要
大小写

此外，您还有一个语法错误-您需要在国家/地区值周围加上单引号。
如果您希望包含“国家/地区”列，则必须将其添加到选择部分：

SELECT
   country, 
   SUM( IF( age BETWEEN 13 AND 17 , 1, 0)) AS '13 - 17', 
   SUM( IF( age BETWEEN 25 AND 45 , 1, 0)) AS '25 - 45', 
   SUM( IF( age BETWEEN 65 AND 75 , 1, 0)) AS '65 - 75'
FROM (SELECT TIMESTAMPDIFF( YEAR, Date_of_birth, CURDATE()) AS age, country FROM data
) AS test
GROUP BY country
HAVING country IN ("france","greece,"spain")

太棒了，谢谢你的快速回复！我将阅读有关聚合列的内容，必须理解其概念！；）几乎，您需要将表数据添加到“FROM”
SELECT country, SUM...., SUM..., SUM...