用於XML名稱輸出列的SQL UNION

Question

我試圖從SQL生成XML輸出，並且需要使用UNION語句並命名輸出列。

我時，我並不需要使用使用UNION語句之前這方面的工作：

select(
SELECT 

    [CompanyName], 
    [Address1], 
    [Address2], 
    [Address3], 
    [Town], 
    [County], 
    [Postcode], 
    [Tel], 
    [Fax], 
    [Email], 
    [LocMap] 

FROM [UserAccs] FOR XML PATH ('AccountDetails'), root ('Root') 
) as XmlOutput 

哪個命名輸出XML列XmlOutput

我現在想：

select(
SELECT 

    [CompanyName], 
    [Address1], 
    [Address2], 
    [Address3], 
    [Town], 
    [County], 
    [Postcode], 
    [Tel], 
    [Fax], 
    [Email], 
    [LocMap] 

FROM [UserAccs] 

UNION 

SELECT 

    [CompanyName], 
    [Address1], 
    [Address2], 
    [Address3], 
    [Town], 
    [County], 
    [Postcode], 
    [Tel], 
    [Fax], 
    [Email], 
    [LocMap] 

FROM [UserAppAccs] 



FOR XML PATH ('AccountDetails'), root ('Root') 
) as XmlOutput 

但收到一條錯誤消息，有沒有人知道解決這個問題的方法？

The FOR XML clause is invalid in views, inline functions, derived tables, and subqueries when they contain a set operator. To work around, wrap the SELECT containing a set operator using derived table syntax and apply FOR XML on top of it. 

感謝 J.

Answer 1

包裹在一個單一的2個選擇，然後做：

select (
    select id, name from (
     select id, name 
     from xmltest 
     UNION 
     select id, name 
     from xmltest 
) A 
FOR XML PATH ('AccountDetails'), root ('Root') 
) As XmlOutput