LEFT JOIN曖昧列到SQL語句中的一列？

Question

是否有可能將LEFT JOIN兩列性質相同，即將t2.Name和t3.Name併入T-SQL語句中的單列（數據屬性）Name？

SELECT t1.ID, 
     t1.RowID, 
     t2.name, 
     t3.Name 
    FROM MasterTable T1 
     LEFT OUTER JOIN RightTable1 T2 
      ON T1.RowID = T2.ID 
     LEFT OUTER JOIN RightTable2 T3 
      ON T1.RowID = T3.ID 
WHERE t1.ID= " & ID & "; 

...還是我必須加載表爲單獨的數據集和編程加入他們（每...下一頁）到一個新的數據集？

問候，

Libor的

Answer 1

SELECT t1.ID, 
     t1.RowID, 
     t2.name + t3.Name AS JoinedName 
    FROM MasterTable T1 
     LEFT OUTER JOIN RightTable1 T2 
      ON T1.RowID = T2.ID 
     LEFT OUTER JOIN RightTable2 T3 
      ON T1.RowID = T3.ID 
WHERE t1.ID= " & ID & "; 

Answer 2

這取決於你的帽子的 「加盟」 的意思是 - 這裏有幾個可能性：

如果一個爲空，另一個是沒有，使用ISNULL：

SELECT DISTINCT 
     t1.ID, 
     t1.RowID, 
     ISNULL(t2.name, t3.Name) Name 
FROM MasterTable T1 
LEFT OUTER JOIN RightTable1 T2 on T1.RowID = T2.ID 
LEFT OUTER JOIN RightTable2 T3 on T1.RowID = T3.ID 

如果你想將它們串聯：

SELECT DISTINCT 
     t1.ID, 
     t1.RowID, 
     t2.name + t3.Name Name 
FROM MasterTable T1 
LEFT OUTER JOIN RightTable1 T2 on T1.RowID = T2.ID 
LEFT OUTER JOIN RightTable2 T3 on T1.RowID = T3.ID 

如果你想兩行（一個UNION）：

SELECT DISTINCT 
     t1.ID, 
     t1.RowID, 
     t2.Name 
FROM MasterTable T1 
LEFT OUTER JOIN RightTable1 T2 on T1.RowID = T2.ID 
UNION ALL 
SELECT DISTINCT 
     t1.ID, 
     t1.RowID, 
     t3.Name 
FROM MasterTable T1 
LEFT OUTER JOIN RightTable2 T3 on T1.RowID = T3.ID 

注意，DISTINCT是必要的，因爲除非你能T2和T3之間的關聯T2和T3你基本交叉聯接（笛卡爾積）所以您需要消除所創建的重複項。