将结果分组为单个列名称

Question

如何将groupby结果作为列名

如果我们使用

的话员工表

  

按性别从员工组中选择计数（*）;给我一个

但我需要它们作为列男|女|无

Answer 1

select sum(case when gender = 'Male' then 1 else 0 end) as 'Male',
sum(case when gender = 'Female' then 1 else 0 end) as 'Female',
sum(case when gender not in ('Male','Female') or gender is null then 1 else 0 end) as 'None'
from staff;