一条语句检索结果

[rion10]

aa:

Name sex
a 0
b 1
c 0
d 0

select count(*) from aa where sex=0
select count(*) from aa where sex=1

如何实现一条语句就能实现？
Select count(*) as man from aa
where Sex=0
inner join
select count(*) as woman from aa
where Sex=1 不行

[rion10]

SELECT 'SEX=0' AS TYPE ,COUNT(*) AS QUANTITY FROM AA WHERE SEX=0?
可以这样吗？数据不对，
应该是这样吧
SELECT SEX,COUNT(*) AS QUANTITY FROM AA WHERE SEX=0 group by sex
但这样不能union了

[happydreamer]

select sum(case sex when 1 then 1 else 0 end) as man,
sum(case sex when 0 then 1 else 0 end) as woman
from aa

[amtyuranus]

select a.man,b.woman from (Select count(*) as man from aa
where Sex=0) as a,(select count(*) as woman from aa
where Sex=1 ) as b

[microyzy]

你想统计男女人数吧？使用group by

select [sex],count(name) 人数 from aa group by sex

[rion10]

aa:

Name sex Age
a 0 20
b 1 30
c 0 20
d 0 30

请问如何在一条语句实现统计sex=0和age=20各有多少人？

[WT滔滔江水]

SELECT 'SEX=0' AS TYPE ,COUNT(*) AS QUANTITY FROM AA WHERE SEX=0
UNION SELECT 'AGE=20' AS TYPE,COUNT(*) AS QUANTITY WHERE AGE=20

[WT滔滔江水]

不好意思写漏了一个 FROM AA
用UNION可以实现的。SQL 帮助多看看吧，很多东西都可以查到的。

[rion10]

pengdali没有完全理解我的意思，我是想同时查出sex=0和age=20分别有多少人啊？能不能一条语句实现
aa:

Name sex Age
a 0 20
b 1 30
c 0 20
d 0 30

请问如何在一条语句实现统计sex=0和age=20各有多少人？

[WT滔滔江水]

to rion10() ,我不是已经帮你解决了吗？快结帐吧

[rion10]

我这边还是不行啊，
SELECT 'SEX=0' AS TYPE ,COUNT(*) AS QUANTITY FROM AA WHERE SEX=0
UNION SELECT 'AGE=20' AS TYPE,COUNT(*) AS QUANTITY WHERE AGE=20
还是出错

[KnowLittle]

出什么错？

[XLYT]

select count(sex),count(age) from aa where sex=0 or age=20

[WT滔滔江水]

你用UNION 就不需要GROUP BY 了。UNION的用法就是列数目要一样。而且像你这样写法也是没必要的SELECT SEX,COUNT(*) AS QUANTITY FROM AA WHERE SEX=0 group by sex，GROUP BY，如果那个WHERE 条件不要的话，可以使用GROUP BY，意思就是求出SEX=1 和SEX=0 的数目各有几个。而你现在已经知道SEX是等于0了所以GROUP BY 可以省略，因为没必要再分组了。

[KnowLittle]

楼上的应该已经很好达到楼主的要求了（虽然有些怪）

[rion10]

还是没弄明白怎么搞,是不是
select count(*) from aa where sex=0
union
select count(*) from aa where age=20

[WT滔滔江水]

你这样也行呀，不过结果集出来就不知道到底哪一行是SEX=0的，AGE=20的了。所以可以在前面多加一列注明一下。
如果要把两列分列出来，可以用CASE

[pengdali]

select sum(case when sex=0 then 1 else 0 end) man,sum(case when sex=1 then 1 else 0 end) woman from aa

[liuzxit]

將大力的略做修改
select sum(case when sex=0 then 1 else 0 end) man,sum(case when age>20 then 1 else 0 end) per from aa

[loujing]

如果查询生成的两个表结构一样，用union好了。

[rion10]

select count(sex),count(age) from aa where sex=0 or age=20??这也可以?
忘说了，我的是mysql，不支持SELECT 'SEX=0' AS TYPE ,COUNT(*) AS QUANTITY FROM AA WHERE SEX=0
UNION SELECT 'AGE=20' AS TYPE,COUNT(*) AS QUANTITY WHERE AGE=20