跪求一条sql统计语句

[haitao00244]

假设有一张A表

table A
id name flag
---------------------------
1 'a' true
2 'b' false
3 'c' true
4 'd' true


现在想用一条sql语句实现统计 flag=false的数量和 flag=true的数量

期望结构如下：select count(id) as y,count(id) as n from A .....

在此先谢啦....

[fatfoxz]

这样行吗？
select count(id) as y, flag from A group by flag

[waterfirer]

问题重了，呵呵
http://topic.csdn.net/u/20090812/14/290b75ad-b187-41b9-89b9-b8fc160c8609.html

[inthirties]

select sum(decode(flag, 'true', 1, 0)) as y, sum(decode(flag, 'false', 1, 0)) n from A;

[cosio]

[Quote=引用 3 楼 inthirties 的回复:]
select sum(decode(flag, 'true', 1, 0)) as y, sum(decode(flag, 'false', 1, 0)) n from A;
[/Quote]

select
sum(case when flag='true' then 1 else 0 end) TRUE个数,
sum(case when flag='false' then 1 else 0 end) FALSE个数
from A;