在查詢中選擇前20行不同的行

每次用戶進入項目時，都會記錄他們查看該項目並標記日期時間。

我想獲得用戶上次進入的TOP 20項目。

這是我到目前爲止有：

SELECT DISTINCT TOP (20) Users_Tran_ID 
FROM App_UserLog 
WHERE (Users_ID = 'ADMIN') AND (Users_Transaction LIKE 'Permit Viewed%') 
ORDER BY App_UserLog.Users_LogDate DESC

的問題是，我不希望在我的輸出Users_LogDate，因爲我需要UNIQUE Users_Tran_ID。

當我從選擇刪除的Users_LogDate我得到以下錯誤：

ORDER BY items must appear in the select list if SELECT DISTINCT is specified.

下面是基本的選擇和結果集，我得到。我只想要明顯的Users_Tran_ID和只有TOP 20.

ADMIN Permit Viewed B2011-0012 2013-08-29 17:35:04.000 
ADMIN Permit Viewed B2011-0012 2013-08-29 17:29:09.000 
ADMIN Permit Viewed B2006-0043 2013-08-29 17:29:05.000 
ADMIN Permit Viewed B2011-0012 2013-08-29 17:28:49.000 
ADMIN Permit Viewed B2008-0167 2013-08-29 17:17:13.000 
ADMIN Permit Viewed B2006-0043 2013-08-29 17:17:08.000 
ADMIN Permit Viewed B2011-0012 2013-08-29 17:16:55.000 
ADMIN Permit Viewed B2011-0012 2013-08-29 17:16:45.000 
ADMIN Permit Viewed B2011-0012 2013-08-29 17:16:38.000 
ADMIN Permit Viewed B2007-0478 2013-08-29 17:16:32.000 
ADMIN Permit Viewed B2011-0012 2013-08-29 11:39:59.000 
ADMIN Permit Viewed B2007-0478 2013-08-29 11:22:05.000 
ADMIN Permit Viewed B2007-0478 2013-08-29 11:22:03.000 
ADMIN Permit Viewed B2011-0012 2013-08-29 10:23:17.000 
ADMIN Permit Viewed B2011-0012 2013-08-29 10:21:58.000 
ADMIN Permit Viewed B2011-0012 2013-08-29 10:20:41.000 
ADMIN Permit Viewed B2011-0012 2013-08-29 10:20:37.000 
ADMIN Permit Viewed B2007-0478 2013-08-29 10:18:01.000 
ADMIN Permit Viewed B2007-0478 2013-08-29 10:17:58.000 
ADMIN Permit Viewed B2011-0012 2013-08-29 10:17:54.000 
ADMIN Permit Viewed B2011-0012 2013-08-29 10:01:50.000 
ADMIN Permit Viewed B2011-0012 2013-08-29 10:01:48.000 
ADMIN Permit Viewed B2007-0478 2013-08-29 09:56:32.000 
ADMIN Permit Viewed B2007-0478 2013-08-29 09:53:31.000 
ADMIN Permit Viewed B2007-0478 2013-08-29 09:53:27.000 
ADMIN Permit Viewed ENG2012-0141 2013-08-15 12:51:09.000 
ADMIN Permit Viewed ENG2012-0141 2013-08-15 12:51:07.000 
ADMIN Permit Viewed BLD2012-0094 2013-08-13 12:01:39.000 
ADMIN Permit Viewed ENG2013-0047 2013-08-05 10:40:34.000 
ADMIN Permit Viewed ENG2013-0047 2013-08-05 10:40:28.000 
ADMIN Permit Viewed ENG2013-0047 2013-08-05 10:40:24.000 
ADMIN Permit Viewed ENG2013-0047 2013-08-05 10:40:21.000 
ADMIN Permit Viewed ENG2013-0047 2013-08-05 10:40:13.000 
ADMIN Permit Viewed ENG2013-0047 2013-08-05 10:40:09.000 
ADMIN Permit Viewed ENG2013-0047 2013-08-05 10:40:07.000 
ADMIN Permit Viewed ENG2012-0141 2013-08-05 10:37:55.000 
ADMIN Permit Viewed ENG2012-0141 2013-08-05 10:37:50.000 
ADMIN Permit Viewed ENG2012-0141 2013-08-05 10:37:46.000 
ADMIN Permit Viewed ENG2012-0141 2013-08-05 10:37:40.000 
ADMIN Permit Viewed ENG2012-0141 2013-08-05 10:37:33.000 
ADMIN Permit Viewed ENG2012-0141 2013-08-05 10:37:31.000 
ADMIN Permit Viewed BLD2012-0919 2013-08-05 10:27:21.000 
ADMIN Permit Viewed BLD2012-0919 2013-08-05 10:27:17.000 
ADMIN Permit Viewed ENG2012-0119 2013-08-05 10:26:51.000 
ADMIN Permit Viewed ENG2012-0119 2013-08-05 10:26:48.000

我該怎麼做？

來源

2013-08-29 Bitco Software

是每個項目的交易ID？在查詢中沒有看到任何標識項目的內容？ – Brian

Users_Tran_ID包含我需要的PROJECT號碼。我將編輯的第一行，我真的只需要Users_Tran_ID在我的最終結果。 –

SELECT Users_ID, Users_Transaction, Users_Tran_ID 
FROM (
    SELECT DISTINCT TOP (20) Users_ID, Users_Transaction, Users_Tran_ID, Users_LogDate 
    FROM App_UserLog 
    WHERE (Users_ID = 'ADMIN') AND (Users_Transaction LIKE 'Permit Viewed%') 
    ORDER BY App_UserLog.Users_LogDate DESC 
) as a

來源

2013-08-29 23:59:21 FrankPl

幾乎有它，但謝謝...那工作： SELECT DISTINCT TOP 20 Users_Tran_ID FROM（SELECT DISTINCT TOP（20）Users_ID，Users_Transaction，Users_Tran_ID，Users_LogDate FROM App_UserLog WHERE（Users_ID ='ADMIN'）AND（Users_Transaction LIKE' Permit Viewed％'）ORDER BY App_UserLog.Users_LogDate DESC）t –

我錯了..沒有工作。 –

@BitcoSoftware什麼是錯誤信息？ – FrankPl

你想用group by而非distinct：

SELECT TOP (20) Users_Tran_ID 
FROM App_UserLog 
WHERE (Users_ID = 'ADMIN') AND (Users_Transaction LIKE 'Permit Viewed%') 
GROUP BY Users_Tran_ID 
ORDER BY max(App_UserLog.Users_LogDate) DESC;

具有聚合，則可以指定要由最近的LOGDATE訂購。瞧，那應該做你想做的。

來源

2013-08-30 00:55:43

您正在尋找這樣的事情：

SELECT TOP 20 Users_ID, 
       Users_Transaction, 
       Users_Tran_ID 
     FROM (SELECT Users_ID, 
         Users_Transaction, 
         Users_Tran_ID, 
         max(Users_LogDate) as MaxUsers_LogDate 
        FROM App_UserLog 
       WHERE (Users_ID = 'ADMIN') AND 
         (Users_Transaction LIKE 'Permit Viewed%') 
       GROUP BY Users_ID, Users_Transaction, Users_Tran_ID 
      ) AS TopTransactions 
ORDER BY MaxUsers_LogDate DESC

見SQLFIDDLE

來源

2013-08-30 02:32:19

在查詢中選擇前20行不同的行

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