Question

我正在尝试编写mysql查询，该查询将通过某个选择的年龄获取有关不同地区的用户数量的数据。例如：如果我选择年龄0-14岁，我想知道“北方”，“南方”等有多少用户在0到14岁之间。

我正在撰写当前的查询：

SELECT sum(case when districts.`districtId` = 1 then 1 else 0 end) as 'North',
    sum(case when districts.`districtId` = 4 then 1 else 0 end) as 'Center',
    sum(case when  districts.`districtId` = 6 then 1 else 0 end) as 'South', , (DATE_FORMAT(NOW(), '%Y') - DATE_FORMAT(userDetails.birthDate2, '%Y') - (DATE_FORMAT(NOW(), '00-%m-%d') < DATE_FORMAT(userDetails.birthDate2, '00-%m-%d'))) as age

来自....年龄在0到14岁之间但我得到错误：未知年龄栏。还有其他方法可以写这个查询吗？！

Answer 1

尝试

SELECT districts.districtId, count(userDetails.*)
FROM userDetails, districts
INNER JOIN districts ON userDetails.districtId = districts.districtId
WHERE userDetails.birthDate2 >= (DATE_SUB(NOW(), INTERVAL 14 YEAR)
AND userDetails.birthDate2 <= (DATE_SUB(NOW(), INTERVAL 0 YEAR)
GROUP BY districts.districtId

对于您的其他问题，请尝试发布数据库架构..

编辑：我忘记了GROUP BY Clausse

Answer 2

由于您未提供完整查询，请尝试此操作，并填写您的值：

 Select districts.districtId, count(*) as DistrictwiseCount From ... Where age_criterion_goes_here
    Group By districts.districtId

按选定年龄计算来自不同地区的用户

2 个答案: