从 SQL Server 2014 中的 FOR XML PATH() 中删除嵌套 SELECT 语句中的 XML 标记答案

【问题标题】：Removing XML-Tags in nested SELECT-Statement from FOR XML PATH() in SQL Server 2014从 SQL Server 2014 中的 FOR XML PATH() 中删除嵌套 SELECT 语句中的 XML 标记
【发布时间】：2019-12-28 00:38:28
【问题描述】：

我需要从嵌套的 sql 语句中删除 xml-tags：

SELECT STUFF(
    (
        SELECT Mailbox
        FROM dbo.Mailbox
        WHERE UnitGroup IN (
            SELECT a.Groups
            FROM (
                SELECT DISTINCT ID, GroupFC AS Groups
                FROM dbo.v_Pending

                UNION ALL

                SELECT DISTINCT ID, GroupBN AS Groups
                FROM dbo.v_Pending

                UNION ALL

                SELECT DISTINCT ID, GroupRM AS Groups
                FROM dbo.v_Pending
            ) AS a
            WHERE a.Groups IS NOT NULL
            AND a.ID = 12345
        )
        FOR XML PATH('')
    ), 1, 0, ''
) AS Mails

我用FOR XML PATH('') 语句尝试过，但它不起作用。也许有人知道错误。我总是得到 xml-tags -.-

目前结果如下：

<Mailbox>abc@xyz.com;</Mailbox>
<Mailbox>def@xyz.com;</Mailbox>

【问题讨论】：

你希望它返回什么？

标签： sql sql-server tsql sql-server-2014

【解决方案1】：

我找到了解决问题的方法。我必须在嵌套的 SELECT-Statement 中添加一个空字符串 '':

SELECT STUFF(
    (
        SELECT '' + Mailbox
        FROM dbo.Mailbox
        WHERE UnitGroup IN (
            SELECT a.Groups
            FROM (
                SELECT DISTINCT ID, GroupFC AS Groups
                FROM dbo.v_Pending

                UNION ALL

                SELECT DISTINCT ID, GroupBN AS Groups
                FROM dbo.v_Pending

                UNION ALL

                SELECT DISTINCT ID, GroupRM AS Groups
                FROM dbo.v_Pending
            ) AS a
            WHERE a.Groups IS NOT NULL
            AND a.ID = 12345
        )
        FOR XML PATH('')
    ), 1, 0, ''
) AS Mails

【讨论】：