如何在GROUP BY和ORDER BY中使用多列但仅使用一列

问题描述

我想显示联接表中的多列，但仅对group by和order by使用一列

我的PostgreSQL查询是这样的：

SELECT disTINCT ON (r.id_rekrutmen)
       r.id_rekrutmen,r.judul_rekrutmen,rw.tanggal_rekrutmen
FROM rekrutmen r
   INNER JOIN rekrutmen_waktu rw
      ON r.id_rekrutmen = rw.id_rekrutmen
ORDER BY r.id_rekrutmen,rw.tanggal_rekrutmen DESC;

解决方法

我想这就是你想要的：

SELECT 
           r.id_rekrutmen,r.judul_rekrutmen,MAX(rw.tanggal_rekrutmen) AS tanggal_rekrutmen
    FROM rekrutmen r
       INNER JOIN rekrutmen_waktu rw
          ON r.id_rekrutmen = rw.id_rekrutmen
    GROUP BY 
           r.id_rekrutmen,