sql-server - SQL UNION FOR XML 名称输出列

Question

我正在尝试从 SQL 生成 XML 输出，需要使用 UNION 语句并命名输出列。

当我不需要使用 UNION 语句时，我之前就使用了以下方法:

select(
SELECT

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

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

将输出 XML 列命名为 XmlOutput

我现在正在尝试:

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

但是收到错误消息，有人知道解决这个问题的方法吗？

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.

谢谢J.

Answer 1

将 2 个选择包裹在一个选择上，如下所示:

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