我如何使用SQL和列值轉換爲XML元素名稱FOR XML

Question

我在MyTable的錶行：

MessageID EMailAddress  DisplayName RecipientType 
1   joe@email.com  Joe   To 
1,  Bob@email.com  Max   From 
1,  Max@email.com  NULL  To 
1,  Secret@email.com Secret  Bcc 

我試圖將其轉換爲XML，看起來像下面這樣：

<to> 
    <displayName>Joe</displayName> 
    <address>joe@email.com</address> 
</to> 
<from> 
    <displayName>Bob</displayName> 
    <address>Bob@email.com</address> 
</from> 
<to> 
    <address>Max@email.com</address> 
</to> 
<bcc> 
    <displayName>Secret</displayName> 
    <address>Secret@email.com</address> 
</bcc> 

我很接近，但無法弄清楚如何將RecipientType轉換成父元素的另外兩列

SELECT 
a.EmailAddress as address, 
a.DisplayName as displayName 
FROM MyTable a 
WHERE a.Id = 1 
FOR XML PATH('address'), TYPE 

有沒有辦法讓「FOR XML PATH（'address'）」成爲RecipientType而不是硬編碼的'地址'？還是有另一種選擇？

我也試過玩過PIVOT，但它似乎沒有幫助。

我知道我可以使用動態SQL，但我試圖遠離那個。

Answer 1

with data as (
    select * from (
    values (1, 'joe@email.com', 'Joe', 'To', 1), 
      (1, 'Bob@email.com', 'Bob', 'From', 2), 
      (1, 'Max@email.com', null, 'To', 3), 
      (1, 'Secret@email.com', 'Secret', 'Bcc', 4) 
    ) t(MessageID, EMailAddress, DisplayName, RecipientType, Ordering) 
    where MessageID = 1 
), pivoted as (
    select * 
    from data pivot (max(EmailAddress) for RecipientType in ([To], [From], [Bcc])) t 
) 
select (case when [To] is not null then DisplayName else null end) as 'to/displayName', [To] as 'to/address', 
     (case when [From] is not null then DisplayName else null end) as 'from/displayName', [From] as 'from/address', 
     (case when [Bcc] is not null then DisplayName else null end) as 'bcc/displayName', [Bcc] as 'bcc/address' 
from pivoted 
order by Ordering 
for xml path('') 

Answer 2

也許這可以讓你開始： 我認爲你將需要一個元素，不管。

DECLARE @data XML; 

SET @data = 

N' 
<root> 
<to> 
    <displayName>Joe</displayName> 
    <address>joe@email.com</address> 
</to> 
<from> 
    <displayName>Bob</displayName> 
    <address>Bob@email.com</address> 
</from> 
<to> 
    <address>Max@email.com</address> 
</to> 
<bcc> 
    <displayName>Secret</displayName> 
    <address>Secret@email.com</address> 
</bcc> 
</root>'; 




SELECT 
     T.myAlias.value('(.)[1]', 'VARCHAR(32)') AS emailAddress 
    , T.myAlias.value('fn:local-name(..)', 'nvarchar(50)') as t 
FROM 
    @data.nodes('//address') AS T(myAlias) 
where 
    T.myAlias.value('fn:local-name(..)', 'nvarchar(50)') = 'to' 
; 

結果：

emailAddress      t 
-------------------------------- -------------------------------------------------- 
joe@email.com     to 
Max@email.com     to 

---

SELECT 

     T.myAlias.value('(.)[1]', 'VARCHAR(32)') AS emailAddress 
    , T.myAlias.value('(../displayName)[1]', 'VARCHAR(32)') AS displayName 
    , T.myAlias.value('fn:local-name(..)', 'nvarchar(50)') as RecipientType 
FROM 
    @data.nodes('//address') AS T(myAlias) 

; 


emailAddress      displayName      RecipientType 
-------------------------------- -------------------------------- 
joe@email.com     Joe        to 
Bob@email.com     Bob        from 
Max@email.com     NULL        to 
Secret@email.com     Secret       bcc 

有除標識的一切。

一個問題，position（）在Xml Shredding中不完全支持。 ：<

http://connect.microsoft.com/SQLServer/feedback/details/383888/fully-support-position-in-xquery

，也看到了這個帖子：

Finding node order in XML document in SQL server