我想重写这个sql查询,以便他显示对应年龄范围的0记录,如果没有匹配,我想让他计算成员的每个值的百分比,而不是'0'在这个时刻,谁能帮助我如何实现这一点?
SELECT COUNT(Name) * 100 /
(select COUNT(*) from 'cities'
WHERE city= 'Hoeselt' AND Member = '0' ) AS 'perc',
CASE
WHEN age <= 30 THEN '18-30'
WHEN age <= 50 THEN '31-50'
ELSE '50+'
END AS age, COUNT(*) AS n
FROM 'cities'
WHERE city= 'Hoeselt' AND elected='yes' AND Member= '0'
GROUP BY CASE
WHEN age <= 30 THEN '18-30'
WHEN age <= 50 THEN '31-50'
ELSE '50+'
END
如果没有DDL,很难确定这是否适用于您。这是一个很好的工具,可以帮助人们给你最好的解决方案。http://sqlfiddle.com/!6
;WITH AgeCat AS
(
SELECT MinAge = 18
,MaxAge = 30
,Descr = '18-30' UNION ALL
SELECT 31, 49, '31-49' UNION ALL
SELECT 50, 200, '50+'
)
SELECT DISTINCT
C.Descr
,Perc = COUNT(*) OVER (PARTITION BY 0) / COUNT(*) OVER (PARTITION BY A.Descr) * 100
FROM AgeCat A
JOIN Cities C ON C.Age BETWEEN A.MinAge AND A.MaxAge
WHERE city = 'Hoeselt'
AND elected = 'yes'
AND Member = '0'
我的方法是使用CTE来定义年龄组。接下来选择所有年龄组作为"司机"表,左边加入城市信息。然后,即使没有匹配,也有年龄组:
with c as (
select c.*,
(CASE WHEN age <= 30 THEN '18-30'
WHEN age <= 50 THEN '31-50'
ELSE '50+'
END) as agegrp
from cities
)
select COUNT(Name) * 100 / (select COUNT(*) from cities WHERE city= 'Hoeselt' AND Member = '0') as perc,
driver.agegrp,
COUNT(*) as n
from (select distinct agegrp from c) as driver left outer join
c
on driver.agegrp = c.agegrp
group by driver.agegrp