Sql如何獲得MAX和MIN Historydata以及相應的用戶

Question

我有HistoryDate和User這個表。 我需要查詢Max（歷史日期），用戶對應Maxdate，Min（HistoryDate），對應每個ReviewID的MinDate用戶

   ModifiedDate |ModifiedBy| CreatedDate  | CreatedBy |ReviewId
  2/16/17 12:58 | Susan    | 2/7/17 15:39 | John      | 1
  2/15/17 13:25 | Sam      | 2/9/17 20:27 | John      | 2

我能夠使用表變量查詢它，但想知道任何其他方式來獲取它。

Answer 1

在FROM子句中使用子查詢來獲取每個min和max。 為了獲得每次審核的最小/最大值，您需要使用GROUP BY ReviewID如下所示：

SELECT max.date AS maxDate, max.user AS maxUser, min.date AS minDate, 
min.user AS minUser
FROM (
    (SELECT MAX(HistoryDate) date, user, ReviewID
    FROM HistoryTable
    GROUP BY ReviewID) max
        JOIN 
    (SELECT MIN(HistoryDate) date, user, ReviewID
    FROM HistoryTable
    GROUP BY ReviewID) min
        ON max.ReviewID = min.ReviewID
)

Answer 2

嗨幾天玩腳本后，這對我有用。

SELECT ModifiedDate, ModifiedBy, CreatedDate ,CreatedBy,  crt.ReviewID 
     FROM   (SELECT  HistoryDate  CreatedDate, ReviewId,   [User] CreatedBy FROM HistoryTable 
        WHERE HistoryDate in (SELECT min(HistoryDate)  FROM  HistoryTable GROUP BY ReviewID )) crt
INNER JOIN
    (SELECT HistoryDate  ModifiedDate, ReviewID, [User] ModifiedBy FROM  HistoryTable 
        WHERE HistoryDate in (SELECT Max(HistoryDate)  FROM HistoryTable GROUP BY ReviewID )) Modi
ON crt.ReviewId = Modi.ReviewID
         ORDER BY crt.ReviewID