TSQL -Eliminating重複從ResultSet和他們在一個單行

結合我有一個表稱爲員工具有以下字段TSQL -Eliminating重複從ResultSet和他們在一個單行

 
Id | Name  | PrimaryEmail1 | PrimaryEmail2 | PrimaryEmail3 
1 | JonSkeet | NULL   | NULL   | [email protected] 
1 | JonSkeet | NULL   | [email protected] | [email protected] 
1 | JonSkeet | [email protected] | NULL   | [email protected] 
2 | George | [email protected] | NULL   | NULL 
2 | George | NULL   | [email protected] | NULL 
2 | George | NULL   | NULL   | [email protected]

如何寫一個TSQL查詢，這樣我可以得到下面的結果集？

 
Id | Name  | PrimaryEmail1 | PrimaryEmail2 | PrimaryEmail3 
1 | JonSkeet | [email protected] | [email protected] | [email protected] 
2 | George | [email protected] | [email protected] | [email protected]

來源

2012-02-01 user992910

是你有什麼不同的值PrimaryEmail3爲JonSkeet？ – gbn 2012-02-01 12:47:35

MAX將消除空值

SELECT 
    ID, Name, 
    MAX(PrimaryEmail1) AS PrimaryEmail1, 
    MAX(PrimaryEmail2) AS PrimaryEmail2, 
    MAX(PrimaryEmail3) AS PrimaryEmail3 
FROM 
    employee 
GROUP BY 
    ID, Name

但是，你的JonSkeet例子顯示PrimaryEmail3是一樣的。你會期望每個ID +名稱有不同的值嗎？如果是這樣，除非您選擇最大值（或最小值），否則不能合併成一行。

這是假設的Id-Name對過於一致

來源

2012-02-01 12:48:53 gbn

是的，我從你的查詢得到了預期的結果。謝謝。我無法編輯我的問題，因爲它顯示了一些格式錯誤。再次感謝。 – user992910 2012-02-01 13:07:59

下面的腳本將串連所有唯一的非NULL電子郵件到一個列表，分別對每列：

; 
WITH employee (Id, Name, PrimaryEmail1, PrimaryEmail2, PrimaryEmail3) AS (
    SELECT 1, 'JonSkeet', NULL   , NULL   , '[email protected]' UNION ALL 
    SELECT 1, 'JonSkeet', NULL   , '[email protected]', '[email protected]' UNION ALL 
    SELECT 1, 'JonSkeet', '[email protected]', NULL   , '[email protected]' UNION ALL 
    SELECT 2, 'George' , '[email protected]' , NULL   , NULL UNION ALL 
    SELECT 2, 'George' , NULL   , '[email protected]' , NULL UNION ALL 
    SELECT 2, 'George' , NULL   , NULL   , '[email protected]' 
) 

SELECT 
    Id, 
    Name, 
    PrimaryEmail1 = SUBSTRING(
    (SELECT DISTINCT ', ' + PrimaryEmail1 FROM employee WHERE Id = e.Id FOR XML PATH ('')), 
    3, 
    999999 
), 
    PrimaryEmail2 = SUBSTRING(
    (SELECT DISTINCT ', ' + PrimaryEmail2 FROM employee WHERE Id = e.Id FOR XML PATH ('')), 
    3, 
    999999 
), 
    PrimaryEmail3 = SUBSTRING(
    (SELECT DISTINCT ', ' + PrimaryEmail3 FROM employee WHERE Id = e.Id FOR XML PATH ('')), 
    3, 
    999999 
) 
FROM employee e 
GROUP BY Id, Name

如果有永遠不能在同一名員工的三個PrimaryEmail列中的任何一列中都有不同的非空值，您將得到與MIN或MAX相同的結果。否則，你會得到所有的不同值的列表，上面的腳本

結果：

Id Name  PrimaryEmail1 PrimaryEmail2 PrimaryEmail3  
-- -------- -------------- ------------- ----------------- 
1 JonSkeet [email protected] [email protected] [email protected] 
2 George [email protected] [email protected] [email protected]

來源

2012-02-01 15:24:38

TSQL -Eliminating重複從ResultSet和他們在一個單行

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