拼合SQL 4個表

Question

在SQL Server 2012中，我有一個看起來像四個表：

Issues：

IssueID | IssueTitle 
1  | Light Bulb Burnt Out 
2  | Thermostat not working 

LocationTypes：

TypeID | Type 
1  | Building 
2  | Floor 
3  | Room 

Locations：

LocaltionID | TypeID | Location  | ParentLocation 
0   | 1  | default  | 0 
1   | 1  | Sears Tower | 0 
2   | 1  | IDS   | 0 
3   | 2  | Floor 1  | 1 
4   | 2  | Floor 2  | 1 
5   | 2  | Floor 3  | 1 
6   | 2  | Floor 4  | 1 
7   | 2  | Floor 5  | 1 
8   | 2  | Floor 6  | 1 
9   | 2  | Floor 7  | 1 
10   | 2  | Floor 8  | 1 
108   | 3  | Room 101  | 3 
109   | 3  | Room 102  | 3 
110   | 3  | Room 110  | 3 
111   | 3  | Room 202  | 4 
112   | 3  | Room 300  | 5 
175   | 2  | 1st Floor  | 2 
185   | 2  | 2nd Floor  | 2 
186   | 3  | Suite 295  | 185 

IssueLocations：

IssueID | LocationId 
1  | 1   
1  | 5   
1  | 112 
2  | 2 
2  | 185 

而我想要做的就是結合表，這樣我結束了一行每間發行機構，與字段名稱爲列標題和字段值，所以我結束了：

結果：

IssueID | IssueTitle    | Building  | Floor  | Room 
-------------------------------------------------------------------------- 
1  | Light Bulb Burnt Out | Sears Tower | Floor 1 | Room 300 
2  | Thermostat not working | IDS   | 2nd Floor | 

注意的第二個問題沒有一個房（無位置爲必填項），位置少的問題是有效的。請注意，其他約束可能導致所需的位置，但我認爲這與此問題無關。

Answer 1

您需要使用Pivot至轉置您的行爲列。

SQL FIDDLE DEMO

SELECT * 
FROM (SELECT il.IssueID, 
       l.Location, 
       i.IssueTitle, 
       lt.Type 
     FROM Locations l 
       JOIN LocationTypes lt 
       ON l.TypeID = lt.TypeID 
       JOIN IssueLocations il 
       ON il.LocationId = l.LocaltionID 
       JOIN issues i 
       ON i.IssueID = il.IssueID) a 
     PIVOT (Max(location) 
      FOR type IN([Building], 
         [Floor], 
         [Room]))piv