使用SQL XML获取dc:creator的价值

Question

我不确定如何使用SQL从RSS-feed获取dc:creator的值.这是我的xml/rss-feed:

<rss xmlns:dc="http://purl.org/dc/elements/1.1/" version="2.0">
<channel>
  <title>Foobar RSS</title>
  <link>http://www.foobar.com/</link>
  <description>RSS feed</description>
  <language>en</language>
  <ttl>15</ttl>
    <item>
        <title>This is my title</title>
        <link>http://www.foobar.com/link/blabla</link>
        <description>Bla..bla..bla..</description>
        <dc:creator>John Doe</dc:creator>
        <guid isPermaLink="false">00082EA751F1D905DE00E7CFA2417DA9</guid>
        <pubDate>Wed, 26 Oct 2011 00:00:00 +0200</pubDate>
    </item>
</channel>
</rss>

在我的SQL中,我使用这样的东西来获取值 - 例如对于pubDate,我使用这样的东西:

DECLARE @xml XML
SET @xml = cast('my rss feed here' AS xml) 

SELECT
convert(datetime,substring(T.nref.value('pubDate[1]','nvarchar(100)'),6,20)) as pubdate,
FROM @xml.nodes('//item') AS T(nref)

这工作正常,但当我试图获得dc:creator值'John Doe'时,以下只是给出了一个错误:

SELECT
   T.nref.value('dc:creator','nvarchar(100)') as creator
FROM @xml.nodes('//item') AS T(nref)

   error: 
   XQuery [value()]: The name "dc" does not denote a namespace.

我需要能够从rss-feed中选择多个列.任何人都可以提供解决方案或方向来获得dc:creator的价值吗？

我有另一个问题 - 如果你在子选择中这样做,你将如何构造代码？

E.g. 
INSERT INTO RSSResults (ID, pubDate)
SELECT @ID, tbl.pubDate FROM (     

;WITH XMLNAMESPACES('http://purl.org/dc/elements/1.1/' AS dc) 
    SELECT 
       RSS.Item.value('(dc:creator)[1]', 'nvarchar(100)') as pubDate
    FROM 
       @xml.nodes('/rss/channel/item') as RSS(Item)) AS tbl 

代码在"; WITH XMLNAMESPACES"中断.是否有可能以某种方式直接在语句中包含命名空间？

Answer 1

尝试这样的事情:

DECLARE @xml XML
SET @xml = cast('my rss feed here' AS xml) 

;WITH XMLNAMESPACES('http://purl.org/dc/elements/1.1/' AS dc)
SELECT
    @xml.value('(rss/channel/item/dc:creator)[1]', 'nvarchar(100)')

如果你需要捕获多个项目 - 试试这个:

DECLARE @xml XML
SET @xml = cast('my rss feed here' AS xml) 

;WITH XMLNAMESPACES('http://purl.org/dc/elements/1.1/' AS dc)
SELECT
    RSS.Item.value('(dc:creator)[1]', 'nvarchar(100)')
FROM
    @xml.nodes('/rss/channel/item') as RSS(Item)