Question

一个表 有两个字段： 姓名（name） 性别（sex），求 用一条sql 语句查出男生、女生各有多少人！

Answer 1

select Count(name) as '男生总数' from table where sex='男'
union
select Count(name) as '男生总数' from table where sex='女'

Answer 2

select sum(case when sex='男' then 1 else 0 end),
sum(case when sex='女' then 1 else 0 end)
from tab

追问

then 1 else 0 end 是干嘛的？？？

追答

如果是男人，统计＋1，否则为0

Answer 3

SELECT T.SEX,COUNT(*) FROM A_TEST T GROUP BY T.SEX;

Answer 4

select count(sex) from table group by sex

Answer 5

select (select count(*) from test where sex='男') 男,(select count(*) from test where sex='女') 女 from dual;