Mysql 我的sql对计数值求和

此

合计（电子邮件、短信、调查）作为总计
在如何合计三个值时出错
我要总数加上三个数
如何做请帮助我试试这个：

Select Count(Case When an_user_plan.campaign_pid != 0 Then 1 End) As Email,
  Count(Case When an_user_plan.sms_pid != 0 Then 1 End) As Sms,
  Count(Case When an_user_plan.survey_pid != 0 Then 1 End) As Survey,
  sum(Email,Sms,Survey)as total
From an_user_plan 

SELECT SUM(campaign_pid != 0 +
           sms_pid != 0 +
           survey_pid != 0) AS total, ...

虽然没有GROUPBY子句，但可以使用变量-

Select Count(Case When an_user_plan.campaign_pid != 0 Then 1 End) +
  Count(Case When an_user_plan.sms_pid != 0 Then 1 End) +
  Count(Case When an_user_plan.survey_pid != 0 Then 1 End) as total
From an_user_plan 

否则，可以使用子查询-

SELECT @c1:=Count(...), @c2:=Count(...), @c1 + @c2 FROM table

同样由同一用户发布错误消息
SELECT c1, c2, c1 + c2 FROM (
  SELECT Count(...) c1, Count(...) c2 FROM table) t