在SQL Server中爲每條記錄創建行到列

Question

我有一個很大的（ish）數據庫。簡單地把客戶記錄。現在我有兩張桌子;一個是CustomerInfo和PhoneNumbers。一些樣本數據是，

CustomerInfo 
````````````` 
CustID | CustName | CustomerLocation 
--------+---------------+-------------------- 
1  | Paul  | Bristol 
2  | Eugin  | Bournemouth 
3  | Francis  | London 

PhoneNumbers 
```````````` 
PhoneID | CustID | PhoneNumber 
--------+-----------+---------------- 
1  | 1  | 0117123456 
2  | 2  | 0120212345 
3  | 2  | 0784256864 
4  | 3  | 0204587895 

現在，你可以看到，Paul和Francis只有一個號碼，但Eugin有兩個。在一個正常的世界，如果我加入了兩個表，

SELECT 
    c.CustName, 
    p.PhoneNumber 
FROM 
    CustomerInfo c 
    JOIN 
    PhoneNumbers p 
    ON c.CustID = p.CustID 

我會得到，

CustName | PhoneNumber 
------------+-------------------- 
Paul  | 0117123456 
Eugin  | 0120212345 
Eugin  | 0784256864 
Francis  | 0204587895 

這是對的，但我運行另一個查詢需要的結果是，

CustName | PhoneNumber1 | PhoneNumber2 
------------+-------------------+--------------- 
Paul  | 0117123456  | NULL 
Eugin  | 0120212345  | 0784256864 
Francis  | 0204587895  | NULL 

我可以寫一個函數的表變量。但由於這將成爲查詢的一部分，我希望是否有其他解決方案。

編輯 -我想強調的部分，as this is going to be part of a Query, I was hoping if there were any other solution，實際的查詢將是，

SELECT 
    per.[PersonId], 
    per.[ClientReference], 
    sal.SalutationName, 
    per.[FirstName], 
    per.[LastName], 
    per.[DateOfBirth], 
    per.[Password] 
FROM 
    [Customers].[people].[Person] per 
    JOIN 
    [Customers].[people].[Salutation] sal 
    ON sal.SalutationId = per.SalutationId 

我想是，

SELECT 
    per.[PersonId], 
    per.[ClientReference], 
    sal.SalutationName, 
    per.[FirstName], 
    per.[LastName], 
    per.[DateOfBirth], 
    per.[Password], 
    pn.[PhoneNumber1], --Made up column, there is only one column in the pn table 
    pn.[PhoneNumber2] --Made up column, there is only one column in the pn table 
FROM 
    [Customers].[people].[Person] per 
    JOIN 
    [Customers].[people].[Salutation] sal 
    ON sal.SalutationId = per.SalutationId 
    JOIN 
    [Customers].[comms].[PhoneNumber] pn 
    ON per.PersonId = pn.PersonId 

Answer 1

您可以使用ROW_NUMBER()爲每個電話號碼在其客戶ID內給出一個等級，然後將其用於PIVOT的數據：

SELECT CustID, 
     PhoneNumber1 = pvt.[1], 
     PhoneNumber2 = pvt.[2], 
     PhoneNumber3 = pvt.[3], 
     PhoneNumber4 = pvt.[4] 
FROM ( SELECT CustID, 
        PhoneNumber, 
        RowNum = ROW_NUMBER() OVER(PARTITION BY CustID ORDER BY Phonenumber) 
      FROM PhoneNumbers 
     ) AS pn 
     PIVOT 
     ( MAX(Phonenumber) 
      FOR RowNum IN ([1], [2], [3], [4]) -- INCREASE/DECREASE COLUMNS AS REQUIRED 
     ) AS pvt; 

如果您的電話號碼數量未知，並且希望在適用的情況下包含所有電話號碼，我會傾向於使用單個列並顯示逗號分隔列表，您可以使用SQL Server's XML extensions進行此操作。這比使用動態SQL更容易，也爲任何處理的結果更容易，因爲你已經被返回的列的已知數量：

SELECT c.CustID, 
     c.CustName, 
     c.CustomerLocation, 
     PhoneNumbers = STUFF(( SELECT ',' + p.PhoneNumber 
           FROM PhoneNumbers AS p 
           WHERE p.CustID = c.CustID 
           FOR XML PATH(''), TYPE).value('.', 'VARCHAR(MAX)'), 1, 1, '') 
FROM CustomerInfo AS c; 

Answer 2

這是你想要的，樞軸與動態SQL

declare @maxcount as int = (select top 1 count(phonenumber) from PhoneNumbers group by custid order by count(phonenumber) desc) 
declare @dynamicsql as nvarchar(max) = 'select * from 
(
SELECT 
    c.CustName, 
    p.PhoneNumber, 
    ''PhoneNumber''+convert(nvarchar(10),(row_number() over (partition by custname order by c.CustName))) as rn 
FROM 
    CustomerInfo c 
    inner join 
    PhoneNumbers p 
    ON c.CustID = p.CustID 
) as sourcetable 
pivot 
(
    MAX(Phonenumber) 
    FOR rn IN (' 

declare @counter as int = 1 
while (@counter<=@maxcount) 
begin 
set @dynamicsql = @dynamicsql +'[PhoneNumber'+convert(nvarchar(10),@counter)+'],' 
set @counter=@counter+1 
end 

set @dynamicsql = substring(@dynamicsql,0,len(@dynamicsql)) 

set @dynamicsql = @dynamicsql + ') 
) 
as pivottable' 

print @dynamicsql 
exec (@dynamicsql) 

供您參考

Answer 3

由於加雷，我設法ŧ o找到我的解決方案，我已經接受了他的答案，但是我想我會分享我如何獲得理想的結果。這是我用過的SQL。

SELECT 
    per.[PersonId], 
    per.[ClientReference], 
    sal.SalutationName, 
    per.[FirstName], 
    per.[LastName], 
    per.[DateOfBirth], 
    per.[Password], 
    tmpQ.PhoneNumber1, 
    tmpQ.PhoneNumber2 
FROM 
    [Customers].[people].[Person] per 
    JOIN 
    [Customers].[people].[Salutation] sal 
    ON sal.SalutationId = per.SalutationId 
    JOIN 
    (SELECT 
     [PersonId], 
     PhoneNumber1 = pvt.[1], 
     PhoneNumber2 = pvt.[2] 
    FROM (SELECT 
       [PersonId], 
       Number, 
       RowNum = ROW_NUMBER() OVER(PARTITION BY PersonID ORDER BY Number) 
      FROM [Customers].[comms].[PhoneNumber]) AS pn 
      PIVOT (MAX(Number) FOR RowNum IN ([1], [2])) AS pvt 
    ) tmpQ 
    ON tmpQ.PersonId = per.PersonId