查询实战

统计员工性别并返回数据:
select if(gender=1,'man','women') 性别,count(*) from tb_emp group by gender;

统计员工职位并返回数据:

select
    case job when 1 then '班主任'
            when 2 then '讲师'
            when 3 then '学工主管'
            when 4 then '教研主管'
            else '未分配' end 职位,
    count(*)
from tb_emp
group by job;

总结: