垂直列结果到水平

Question

我需要将列结果置于水平位置，就像 SUM(CASE WHEN status = 'On Hold' THEN 1 ELSE 0 END) AS 'word' 那样，我也尝试了子查询和别名 AS，但没有成功。我认为 JOIN 是针对多个表，而 UNION 是为了在同一列中获得结果。

我将此页面用作参考

https://www.mysqltutorial.org/mysql-case-function/

mysql Table: phpvms_pireps

pilotid|flightnum|submitdate|accepted

我的sql代码：

SELECT DISTINCT `phpvms_pireps`.`pilotid`
     , `phpvms_pireps`.`accepted`
     , `phpvms_pireps`.`flightnum`
     , `phpvms_pireps`.`submitdate`
  FROM phpvms_pireps
 WHERE ((`phpvms_pireps`.`flightnum` in ('A-1', 'A-2', 'A-3', 'A-4')))
   AND submitdate BETWEEN '2020-04-09' AND '2020-04-11'
 ORDER 
    BY `phpvms_pireps`.`pilotid` ASC

结果：

我想实现这个：

我正在使用 php/html，如何获得该结果？

非常感谢！

Answer 1

您正在描述一个支点table。考虑使用条件聚合：

select 
    pilotid, 
    max(case when flightnum = 'A-1' then accepted end) a1,
    max(case when flightnum = 'A-2' then accepted end) a2,
    max(case when flightnum = 'A-3' then accepted end) a3,
    max(case when flightnum = 'A-4' then accepted end) a4
from phpvms_pireps 
where 
    flightnum in ('A-1', 'A-2', 'A-3', 'A-4')
    and submitdate between '2020-04-09' and '2020-04-11'
group by pilotid
order by pilotid

垂直列结果到水平

Vertical column result to horizontal

mysql

sql

datetime

pivot

max