Mysql 如何在case语句中添加内容

我的问题如下

select date(created_at), 
  count(distinct  updated = '3'  then user_id end) as unique, 
  count(distinct  updated <> '3' then user_id end) as duplicate1,
  count(distinct  updated_by <> '4' then user_id end) as duplicate2

from user
where date(created_at) between current_date-2 and current_date
group by date(created_at) 

选择日期（创建时），
计数（不同的更新='3'然后用户id结束）为唯一，
计数（不同的更新“3”，然后用户id结束）为重复项1，
计数（由“4”进行不同的更新，然后用户id结束）为重复项2
来自用户
其中日期（创建日期）介于当前日期-2和当前日期之间
按日期分组（创建时间）

---

我还需要一个列，上面写着“重复总数”，它是重复1和重复2的总和

只需添加一个新的条件计数，其中包括两个重复条件：

SELECT
    DATE(created_at),
    COUNT(DISTINCT updated = '3' THEN user_id END) AS unique, 
    COUNT(DISTINCT updated <> '3' THEN user_id END) AS duplicate1,
    COUNT(DISTINCT updated_by <> '4' THEN user_id END) AS duplicate2
    COUNT(DISTINCT updated <> '3' OR updated_by <> '4'
              THEN user_id END) AS total_duplicates
FROM user
WHERE
    DATE(created_at) BETWEEN CURRENT_DATE - 2 AND CURRENT_DATE
GROUP BY
    DATE(created_at);

选择
日期（创建时间），
计数（不同的更新='3'然后用户id结束）为唯一，
计数（不同的更新“3”，然后用户id结束）为重复项1，
计数（由“4”进行不同的更新，然后用户id结束）为重复项2
计数（分别更新了“3”或更新了“4”
然后用户id（结束）作为总重复项
来自用户
哪里
当前日期-2和当前日期之间的日期（创建日期）
分组
日期（创建于）；

如果要计算由“3”更新的

行和由“4”更新的
行，则需要条件：

count(distinct case when updated_by <> '3' and updated_by <> '4' then user_id end)

因此，您的代码应该是：

select date(created_at), 
  count(distinct case when updated_by = '3'  then user_id end) as unique, 
  count(distinct case when updated_by <> '3' then user_id end) as duplicate1,
  count(distinct case when updated_by <> '4' then user_id end) as duplicate2,
  count(distinct case when updated_by not in ('3', '4') then user_id end) as total_duplicates
from user
where date(created_at) between current_date-2 and current_date
group by date(created_at)

select date(created_at), 
  count(distinct case when updated_by = '3'  then user_id end) as unique, 
  count(distinct case when updated_by <> '3' then user_id end) as duplicate1,
  count(distinct case when updated_by <> '4' then user_id end) as duplicate2,
  count(distinct user_id) as total_duplicates
from user
where date(created_at) between current_date-2 and current_date
group by date(created_at)

select date(created_at), 
  count(distinct case when updated_by = '3'  then user_id end) as unique, 
  count(distinct case when updated_by <> '3' then user_id end) as duplicate1,
  count(distinct case when updated_by <> '4' then user_id end) as duplicate2,
  count(distinct user_id) as total_duplicates
from user
where date(created_at) between current_date-2 and current_date
group by date(created_at)