将结果分组为单个列名称

Question

如何将groupby结果作为列名称

如果我们使用员工桌

按性别从工作人员组中选择计数(*); 给我一个

但我需要它们作为列男| 女| 没有

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;