使用您提供的 XML 模式为我工作
DECLARE @XmlTable TABLE (XmlResult XML)
INSERT INTO @XmlTable VALUES ('<books><book><title>GWTW</title></book></books>')
INSERT INTO @XmlTable VALUES ('<foo />')
INSERT INTO @XmlTable VALUES ('<books />')
SELECT
COUNT(*) AS BooksCount
FROM
(
SELECT XmlResult FROM @XmlTable
) AS XmlTable(XmlColumn)
CROSS APPLY XmlColumn.nodes('./books/book') XmlTableFunction(XmlColumn2);
Exist 方法也非常有用。我使用 NULLIF 将 0 更改为 NULL (它有点需要 CAST 和 SUM)
SELECT COUNT(NULLIF(XmlResult.exist('./books/book'), 0)) FROM @XmlTable
编辑,更新后
您发布的 XML 也是错误的。
您没有正确指定根音:
DECLARE @XmlTable TABLE (XmlResult XML)
INSERT INTO @XmlTable VALUES ('
<Version number ="1">
<books>
<book>
<name> </name>
<author></author>
</book>
<book>
<name> </name>
<author></author>
</book>
</books>
</Version>')
SELECT
COUNT(*)
FROM
(
SELECT XmlResult FROM @XmlTable
) AS XmlTable(XmlColumn)
CROSS APPLY XmlColumn.nodes('/Version/books/book') XmlTableFunction(XmlColumn2);
SELECT
COUNT(*)
FROM
(
SELECT XmlResult FROM @XmlTable
) AS XmlTable(XmlColumn)
CROSS APPLY XmlColumn.nodes('*/books/book') XmlTableFunction(XmlColumn2);