如何修改此SQL查詢以獲取位於其他表中的信息？

Question

我使用SQL Server 2014和我有一個使用3個表給我與住客，保留下面的輸出中的簡單查詢：

查詢看起來是這樣的：

USE MyDatabase 

SELECT a.ResID, a.Name, a.Property, c.ArrivalDate,c.DepartureDate,c.ConfNum, 
d.CHAR07, c.StatusCode,c.CreatedOn, c.UpdatedBy, c.CreatedBy 
FROM GuestStaySummary a 
    left join GuestNameInfo b on b.ResID = a.ResID 
    left join reservationstay c on c. ResID = a. ResID 
WHERE a.PrimaryGuest = '+' 

輸出是如下所示：

ResID  Property Name  ArrivalDate DepartureDate ConfNum StatusCode CreatedOn UpdatedBy CreatedBy 
125   ABC  Jones  2015-08-20 2015-08-27 659874  CONFIRMED 2015-03-10  AP01  AP01 

由於系統上的應用程序升級，所有預留都被取消並重新創建。因此，進入上述成了如下：

ResID  Property Name  ArrivalDate DepartureDate ConfNum StatusCode CreatedOn UpdatedBy CreatedBy 
125   ABC  Jones  2015-08-20 2015-08-27 659874  CANCELED 2015-03-10  R5  AP01 
358   ABC  Jones  2015-08-20 2015-08-27 742651  CONFIRMED 2015-05-15  R5  AP01 

原來ResID 125現在有一個StatusCode爲「取消」，並已與新的ResId和新ConfNum重新創建。

ResId 125（現Res ID 358）的原始CreatedOn（即2015-03-10）對我的分析目的非常重要。換句話說，我需要鏈接ResID 358的CreatedOn與2015-03-10而不是它的新的CreatedOn這是2015-05-15。

鏈接這兩個條目的唯一方法是使用已存儲在稱爲的表中的名爲CHAR07的列中的「原始」ConfNum。

我已經修改我的查詢如下檢索「取消」保留所有的名單和他們的等價物「新的」保留：

USE MyDatabase 

SELECT a.ResID, a.Name, a.Property, c.ArrivalDate,c.DepartureDate,c.ConfNum, 
d.CHAR07 AS ‘Original ConfNum’, c.StatusCode,c.CreatedOn, c.UpdatedBy,  c.CreatedBy 
FROM GuestStaySummary a 
    left join GuestNameInfo b on b.ResID = a.ResID 
    left join reservationstay c on c. ResID = a. ResID 
    left join P5RESERVATIONSTAY d on d.RSY_RESERVATIONSTAYID = a.ResID 
    left join P5RESERVATIONSTAY d2 on d2.CHAR07 = c.ConfNum 
WHERE b.PrimaryGuest = '+' 

輸出如下內容：

ResID  Property Name  ArrDate  DepDate  ConfNum  Original ConfNum  StatusCode  CreatedOn UpdatedBy CreatedBy 
125   ABC  Jones  2015-08-20 2015-08-27 659874   NULL    CANCELED 2015-03-10  R5  AP01 
358   ABC  Jones  2015-08-20 2015-08-27 742651   659874    CONFIRMED 2015-05-15  R5  AP01 

它可以完成這項工作，但我需要在Excel中使用VLOOKUP來獲取原始的CreatedOn。

我想我的SQL查詢給我下面的輸出：

ResID Property Name ArrDate  DepDate  ConfNum  Original ConfNum StatusCode  CreatedOn  OriginalCreatedOn UpdatedBy CreatedBy 

358  ABC  Jones 2015-08-20 2015-08-27 742651  659874    CONFIRMED 2015-05-15  2015-03-10  R5  AP01 

我怎樣才能做到這一點？

Answer 1

難道你真的只需要再次回到reservationstay？我認爲內部連接會照顧只包括正確的取消和重新創建的行，但我不是100％確定的，因爲我不知道你有什麼其他數據。

SELECT 
    gss.ResID, gss.Property, gss.Name, rs.ArrivalDate, rs.DepartureDate, rs.ConfNum, 
    p5rs.CHAR07 as "Original ConfNum", rs.StatusCode, rs.CreatedOn, 
    rsorg.CreatedOn as "Original CreatedOn", rs.UpdatedBy, rs.CreatedBy 
FROM 
    GuestStaySummary as gss 
    inner join GuestNameInfo  as gni on gni.ResID = gss.ResID 
    inner join reservationstay as rs on rs.ResID = gss.ResID 
    inner join P5RESERVATIONSTAY as p5rs on p5rs.RSY_RESERVATIONSTAYID = gss.ResID 
    inner join reservationstay as rsorg on rsorg.ConfNum = p5rs.CHAR07 
WHERE 
    gni.PrimaryGuest = '+'