如何将同一表中的总值显示为一行（在case语句中）？

Posted 2023-02-24

【中文标题】如何将同一表中的总值显示为一行（在case语句中）？

【英文标题】：How to display total of values in the same table as a row (in case statement)?

【发布时间】：2019-02-11 07:45:58

【问题描述】：

我有一个问题：

SELECT t.diapason, COUNT(distinct user_id) AS 'number_of_users'
    FROM (SELECT p.user_id, p.amount as total, CASE  
       when amount<=100 then '0-100' 
       when amount>100 and amount<=150 then '100-150' 
       when amount>150 then '>150 +' END AS diapason
       FROM 
         (SELECT payments.user_id, SUM(amount) AS amount 
         FROM payments INNER JOIN (SELECT DISTINCT user_id FROM activity 
          where login_time between '2018-04-12' and '2018-04-18') a ON 
          payments.user_id = a.user_id
          GROUP BY payments.user_id) p) t
GROUP BY t.diapason
ORDER BY number_of_users desc;

我应该如何更改才能将 number_of_users 总数显示为一行？

输出

+----------+-----------------+
| diapason | number_of_users |
+----------+-----------------+
| 0-100    |             278 |
| >150 +   |              16 |
| 100-150  |              12 |
| total    |             306 |    - I need this row
+----------+-----------------+

谢谢！

【问题讨论】：

你的样本数据是什么？

你可以联合

案例表达式。 （返回一个值。）

我可以在dba.stackexchange.com/questions/68791/group-by-in-ranges找到更好的处理sql范围的方法

【参考方案1】：

看看ROLLUP，类似：

SELECT IF(GROUPING(t.diapason), 'total', t.diapason) AS diapason,
       COUNT(distinct user_id) AS 'number_of_users'
FROM (SELECT p.user_id, p.amount as total, CASE  
   when amount<=100 then '0-100' 
   when amount>100 and amount<=150 then '100-150' 
   when amount>150 then '>150 +' END AS diapason
   FROM 
     (SELECT payments.user_id, SUM(amount) AS amount 
     FROM payments INNER JOIN (SELECT DISTINCT user_id FROM activity 
      where login_time between '2018-04-12' and '2018-04-18') a ON 
      payments.user_id = a.user_id
      GROUP BY payments.user_id) p) t
GROUP BY t.diapason WITH ROLLUP;

【讨论】：

谢谢！有用。但它显示：NULL | 306. 如何更改“total”而不是“NULL”？

@ЕлисейГорьков 更新了我的答案，请查看。如果它对您有帮助，请不要忘记接受它作为正确答案。快乐编码！ :)

ERROR 1221 (HY000)：CUBE/ROLLUP 和 ORDER BY 的使用不正确

谢谢，但是...错误 1305 (42000)：FUNCTION businessanalysis.GROUPING 不存在

GROUPING 功能是 mysql 8.0 中的新功能。见mysqlserverteam.com/mysql-8-0-grouping-function

【参考方案2】：

这里已经有一个很好的答案，但万一你不能使用 ROLLUP，你可以使用 UNION：

SELECT t.diapason, COUNT(distinct user_id) AS 'number_of_users'
    FROM (SELECT p.user_id, p.amount as total, CASE  
       when amount<=100 then '0-100' 
       when amount>100 and amount<=150 then '100-150' 
       when amount>150 then '>150 +' END AS diapason
       FROM 
         (SELECT payments.user_id, SUM(amount) AS amount 
         FROM payments INNER JOIN (SELECT DISTINCT user_id FROM activity 
          where login_time between '2018-04-12' and '2018-04-18') a ON 
          payments.user_id = a.user_id
          GROUP BY payments.user_id) p) t
GROUP BY t.diapason
UNION ALL
SELECT 'total' AS diapason, COUNT(distinct user_id) AS 'number_of_users'
    FROM (SELECT p.user_id, p.amount as total, CASE  
       when amount<=100 then '0-100' 
       when amount>100 and amount<=150 then '100-150' 
       when amount>150 then '>150 +' END AS diapason
       FROM 
         (SELECT payments.user_id, SUM(amount) AS amount 
         FROM payments INNER JOIN (SELECT DISTINCT user_id FROM activity 
          where login_time between '2018-04-12' and '2018-04-18') a ON 
          payments.user_id = a.user_id
          GROUP BY payments.user_id) p) t
GROUP BY 1
ORDER BY number_of_users desc;

希望对你有帮助