SQL条件控制（case when...then...else...end） 详细解释

Case具有两种格式。简单Case函数和Case搜索函数
   遇到 xxx情况 就 xxx 遇不到就 xxx结束
   case when …… then…… else……end
           

--简单Case函数
CASE sex
         WHEN '1' THEN '男'
         WHEN '2' THEN '女'
ELSE '其他' END
--Case搜索函数
CASE WHEN sex = '1' THEN '男'
         WHEN sex = '2' THEN '女'
ELSE '其他' END
           

select *,

count(CASE WHEN consultType = 1 then 1 end) as count1,

count(CASE WHEN consultType = 0 then 1 end ) as count2,

count(CASE WHEN consultType = 2 then 1 end) as count3

from jcb_users AS ju INNER JOIN jcb_user_consult_record AS jucr where ju.loginUserId=130

我的例子