如果每次最多有两条记录 clickid 然后您可以使用：

SELECT clickid
FROM TableA
GROUP BY clickid
HAVING MIN(CASE WHEN status = 'low' THEN datetime END) <
       MIN(CASE WHEN status = 'act' THEN datetime END)

此处演示
为了确保一个记录是'low'，而另一个是'act'，您可以将以下 predicate 添加到 HAVING :
SUM(status = 'low') = 1 SUM(status = 'act') = 1

你可以使用自连接

select a.clickid, a.status, b.clickid, b.status 
 from tableA a 
 inner join tableA b on a.clickid = b.clickid 
      and a.datetime < b.datetime 
          and a.status = 'low' 
              and b.status ='act'

尝试加入：

SELECT t1.clickid 
  FROM tableA AS t1
  JOIN tableA AS t2 
    ON t1.clickid = t2.clickid 
   AND t1.status = 'act'
   AND t2.status = 'low' 
   AND t2.datetime < t1.datetime
GROUP BY t1.clickid

这里还有一个演示：http://sqlfiddle.com/#!9/1f861/1/0年

SELECT 

* 

FROM
(SELECT 
    *
FROM
    tableA
WHERE
    status= 'low') a
    INNER JOIN
(SELECT 
    *
FROM
    tableA
WHERE
    status= 'act') b ON a.clickid = b.clickid where a.datetime < b.datetime;