SELECT DISTINCT

Question

我有一個MS SQL查詢

SELECT DISTINCT Date_of_Record, Computer_Name, IP_Address, Agent_Version, Mac_Address 
FROM [SEP_Versions].dbo.Computers 
WHERE Computer_Name in (SELECT Computer_Name 
         FROM [SEP_Versions].dbo.Computers 
         GROUP BY Computer_Name 
         HAVING COUNT(DISTINCT Agent_Version) > 1) 
AND [SEP_Versions].dbo.Computers.COMPUTER_NAME LIKE '%s001' 
AND [SEP_Versions].dbo.Computers.IP_Address LIKE '%.100' 
ORDER BY Computer_Name, Date_of_Record 

輸出

Date  Computer IP    Version   Mac 
2014-10-24 COMP001 10.10.10.10  12.1.3001.165 NULL 
2014-10-25 COMP001 10.10.10.10  12.1.3001.165 NULL 
2014-10-26 COMP001 10.10.10.10  12.1.3001.165 NULL 
2014-10-27 COMP001 10.10.10.10  12.1.4013.4013 NULL 
2014-10-28 COMP001 10.10.10.10  12.1.4013.4013 NULL 
2014-10-29 COMP001 10.10.10.10  12.1.5773.2276 NULL 

如何改變SELECT DISTINCT語句，因此它最早輸出具有鮮明版本記錄日期，即

Date  Computer IP    Version   Mac 
2014-10-24 COMP001 10.10.10.10  12.1.3001.165 NULL 
2014-10-27 COMP001 10.10.10.10  12.1.4013.4013 NULL 
2014-10-29 COMP001 10.10.10.10  12.1.5773.2276 NULL 

@Pradeep

您的解決方案輸出

Date  Computer IP    Version   Mac 
2014-10-17 COMP001 10.10.10.10  12.1.3001.165 NULL 
2014-10-17 COMP002 10.10.10.11  12.1.4013.4013 NULL 
2014-10-17 COMP003 10.10.10.12  12.1.5773.2276 NULL 
2014-10-17 COMP004 10.10.10.14  11.0.5003.2276 NULL 

@ 1010和@AWinkle

如果我運行

SELECT DISTINCT Computer_Name, IP_Address, Agent_Version 
FROM dbo.Computers 
WHERE Computer_Name in (SELECT Computer_Name 
         FROM dbo.Computers 
         GROUP BY Computer_Name 
         HAVING COUNT(DISTINCT Agent_Version) > 1) 
AND dbo.Computers.COMPUTER_NAME LIKE '%s001' 
AND dbo.Computers.IP_Address LIKE '%.100' 
ORDER BY Computer_Name 

然後我得到

Computer IP    Version   Mac 
COMP001 10.10.10.10  12.1.3001.165 NULL 
COMP001 10.10.10.10  12.1.4013.4013 NULL 
COMP001 10.10.10.10  12.1.5773.2276 NULL 

如何修改SQL語句，所以它增加了相應Date_of_Record列

Answer 1

簡單的答案是通過使用窗口函數。

;WITH cte 
    AS (SELECT DISTINCT Row_number() 
          OVER (
          partition BY Computer_Name,Agent_Version 
          ORDER BY Date_of_Record) RN, 
         Date_of_Record, 
         Computer_Name, 
         IP_Address, 
         Agent_Version, 
         Mac_Address 
     FROM [SEP_Versions].dbo.Computers 
     WHERE Computer_Name IN (SELECT Computer_Name 
            FROM [SEP_Versions].dbo.Computers 
            GROUP BY Computer_Name 
            HAVING Count(DISTINCT Agent_Version) > 1) 
       AND [SEP_Versions].dbo.Computers.COMPUTER_NAME LIKE '%s001' 
       AND [SEP_Versions].dbo.Computers.IP_Address LIKE '%.100') 
SELECT Date_of_Record, 
        Computer_Name, 
        IP_Address, 
        Agent_Version, 
        Mac_Address 
FROM cte 
WHERE RN = 1 
ORDER BY Computer_Name, 
      Date_of_Record 

Answer 2

我覺得這是你想要

SELECT MIN(Date_of_Record), Computer_Name, IP_Address, Agent_Version, Mac_Address 
FROM ... 
WHERE ... 
GROUP BY Computer_Name, IP_Address, Agent_Version, Mac_Address 
ORDER BY ... 

group by子句將彙總行的計算機名，IP_ADDRESS AGENT_VERSION，MAC_ADDRESS的每個組合的東西。 MIN（Date_of_Record）將爲每個組計算最早的日期。

Answer 3

在SQL Server中，您不能僅通過選定數量的列來選擇不同列，而需要對它們進行分組。使用MIN函數將在最早的日期提供不同的版本（通過計算機/ ip/mac）。

SELECT MIN(Date_of_Record) Earliest_Date_of_Record, Computer_Name, IP_Address, Agent_Version, Mac_Address 
FROM [SEP_Versions].dbo.Computers 
WHERE Computer_Name in (SELECT Computer_Name 
        FROM [SEP_Versions].dbo.Computers 
        GROUP BY Computer_Name 
        HAVING COUNT(DISTINCT Agent_Version) > 1) 
AND [SEP_Versions].dbo.Computers.COMPUTER_NAME LIKE '%s001' 
AND [SEP_Versions].dbo.Computers.IP_Address LIKE '%.100' 
GROUP BY Computer_Name, IP_Address, Agent_Version, Mac_Address 
ORDER BY Computer_Name, Date_of_Record