加入Max和Max前行

Question

我有兩個表'sites'和'index_log'。表'網站'是關於網站（用戶ID，名稱，描述等）的信息。表索引_日誌具有列日期，索引_計數和網站ID。所以我想最後和以前index_log一行爲每個站點，其中userid = 10，這是我的變種：

SELECT ff.id, 
     ff.siteurl, 
     ff.last_count, 
     ff.last_date, 
     il2.index_count as previous_count, 
     MAX(il2.date) as previous_date 
FROM (
    SELECT s.siteurl, 
      s.id, 
      il.index_count as last_count, 
      MAX(il.date) as last_date 
    FROM sites s 
    LEFT JOIN index_logs il ON il.siteid = s.id 
    WHERE s.userid = 10 
    GROUP BY s.id 
    ) as ff 
LEFT JOIN index_logs il2 ON il2.siteid = ff.id AND il2.date < ff.last_date 
GROUP BY ff.id 

但在這個變體index_count柱（去年及以前）不匹配，最大日起一行。我希望能爲你提供幫助。

Answer 1

這將讓每sites.id

; with CTE as 
(
    SELECT s.siteurl, s.id, il.index_count, il.date, 
      RN = ROW_NUMBER() OVER (PARTITION BY s.id ORDER BY il.date DESC) 
    FROM sites s 
    JOIN index_logs il ON il.siteid = s.id 
    WHERE s.userid = 10 
) 
SELECT * 
FROM CTE 
WHERE RN <= 2