Question

我想写这样的东西

SELECT MIN(date),
       id 
   FROM test 
  WHERE t.SITE_ID=SITE_id 
  GROUP BY SITE_ID

但是在逐个电话之后无法获得id。

然后我想出了这个

SELECT t.id 
  FROM test t 
 WHERE t.date IN(SELECT MIN(date) 
                   FROM test 
                  WHERE t.SITE_ID=SITE_id 
                  GROUP BY SITE_ID)

这个选择应该让我获得与每个站点的最小日期具有相同日期的测试行的id，以便更简单？

Answer 1

尝试

SELECT t1.id 
FROM test t1
inner join
(
   select site_id, min(date) as mdate
   from test
   GROUP BY site_id
) t2 on t1.site_id = t2.site_id and t1.date = t2.mdate

Answer 2

SELECT t1.id 
FROM test t1
inner join
(
   select site_id, min(date) as mdate
   from test
   GROUP BY site_id, id
) t2 on t1.site_id = t2.site_id and t1.date = t2.mdate

获取满足条件的列的ID时分组

2 个答案: