Question

我一直在尝试根据不同月份的年龄差异生成报告，目前我知道的解决方案是分别为每个月和每个年龄差异分别进行sql查询，这样可以为每个月创建4个不同的sql查询。请告诉我是否可以为每个月创建一个SQL查询，如

如果我想为年龄差异超过40，在50-60之间，在60-70和80以上之间生成JAN的报告

我如何将它放在一个SQL查询中并从中获得四个不同的结果

像（仅限一个想法）

Select count(Above 40),count(In Between 50 - 60),count (In B/W 60-70), count(above 80) from users

Answer 1

我将IF（）和SUM（）一起使用如下：

SELECT SUM(IF(age >= 40,1,0))               AS older40, 
       SUM(IF(age >= 50 and age <= 60,1,0)) AS between50and60
       SUM(IF(age >= 60 and age <= 70,1,0)) AS between60and70
       SUM(IF(age >= 80,1,0))               AS over80

FROM TABLE

请参阅IF(expr1,expr2,expr3)的MySQL解释，但基本上expr1是条件，expr2是条件为真时的值，expr3是else。使用1＆amp; 0为这些允许SUM（）计算记录。

Answer 2

尝试类似

的内容

Select Range,Count(*) From
(Select 
Case 
When (Age >= 40 and Age < 50) Then 'Above40'
When (Age >= 50 and Age < 60) Then 'Between 50 - 60'
When (Age >= 60 and Age < 70) Then 'In B/W 60-70'
When (Age > 80) Then 'Above 80'
else 'Not Counted'
end as Range
From Users) as Ranges
Group By Range

猜测看守，因为你似乎有很多空隙和重叠。

Answer 3

select *
from (
(select COUNT(Age) as `c1`, '40-50' AS 'freq' from `Users` WHERE Age BETWEEN 40 AND 50)
UNION ALL
(select COUNT(Age)  as `c2`, '50-60' AS 'freq' from `Users` WHERE Age BETWEEN 50 AND 60)
UNION ALL
(select COUNT(Age)  as `c2`, '60-70' AS 'freq' from `Users` WHERE Age BETWEEN 60 AND 70)
) as aliasquery ;

SQL查询ALL in One - 避免查询次数

3 个答案: