从 SQL 服务器的 XML 列中选择字段时，我没有得到任何结果，也没有错误

Question

我有一个 table 和一个 XML 类型化列，其中包含一个带有命名空间的 XML 结构。 Table 名为 PersonX 它包含一个名为 customData

的 XML 类型列

customData 列包含此结构：

<personX:CustomData xmlns:personX="http://www.provider.com/PersonX">
    <MailingStreet>123 First Street, APT 123</MailingStreet>
    <MailingCity>Dallas</MailingCity>
    <MailingState>TX</MailingState>
    <MailingZip>73425</MailingZip>
    <ResidenceCity>Dallas</ResidenceCity>
    <ResidenceCounty>Dallas</ResidenceCounty>
    <ExportDate>2021-05-19T00:00:00Z</ExportDate>
    <IssueDate>2021-05-18T00:00:00Z</IssueDate>
    <ExpireDate>2022-05-23T00:00:00Z</ExpireDate>
    <SubmissionDate>2021-05-03T00:00:00Z</SubmissionDate>
</personX:CustomData>

我的查询：

declare @xml xml
select @xml = customData from PersonX

;with xmlnamespaces('http://www.provider.com/PersonX' as ns, DEFAULT 'http://www.provider.com/PersonX')
select Person.x.value('MailingStreet[1]','varchar(max)') as street
from @xml.nodes('personX') as Person(x)

当我运行时，我得到一个空白的街道值。我认为这与根元素中的冒号有关

我想我错过了一些简单的东西？

还有一个额外的问题，我如何运行 table 本身的查询而不是选择变量？

Answer 1

请尝试以下解决方案。

直接来自table，没有临时变量。

不需要定义同一个命名空间两次。

SQL

-- DDL and sample data population, start
DECLARE @tbl table (ID INT IDENTITY PRIMARY KEY, customData XML);
INSERT INTO @tbl ( customData) VALUES
(N'<personX:CustomData xmlns:personX="http://www.provider.com/PersonX">
    <MailingStreet>123 First Street, APT 123</MailingStreet>
    <MailingCity>Dallas</MailingCity>
    <MailingState>TX</MailingState>
    <MailingZip>73425</MailingZip>
    <ResidenceCity>Dallas</ResidenceCity>
    <ResidenceCounty>Dallas</ResidenceCounty>
    <ExportDate>2021-05-19T00:00:00Z</ExportDate>
    <IssueDate>2021-05-18T00:00:00Z</IssueDate>
    <ExpireDate>2022-05-23T00:00:00Z</ExpireDate>
    <SubmissionDate>2021-05-03T00:00:00Z</SubmissionDate>
</personX:CustomData>');
-- DDL and sample data population, end

WITH XMLNAMESPACES ('http://www.provider.com/PersonX' AS personX)
SELECT ID
    , c.value('(MailingStreet/text())[1]', 'VARCHAR(50)') AS MailingStreet
    , c.value('(MailingCity/text())[1]', 'VARCHAR(50)') AS MailingCity
FROM @tbl
CROSS APPLY customData.nodes('/personX:CustomData') AS t(c);

-- if enforced by the XML Schema
WITH XMLNAMESPACES ('http://www.provider.com/PersonX' AS personX)
SELECT ID
    , c.value('(MailingStreet)[1]', 'VARCHAR(50)') AS MailingStreet
    , c.value('(MailingCity)[1]', 'VARCHAR(50)') AS MailingCity
FROM @tbl
CROSS APPLY customData.nodes('/personX:CustomData') AS t(c);

输出

+----+---------------------------+-------------+
| ID |       MailingStreet       | MailingCity |
+----+---------------------------+-------------+
|  1 | 123 First Street, APT 123 | Dallas      |
+----+---------------------------+-------------+

从 SQL 服务器的 XML 列中选择字段时，我没有得到任何结果，也没有错误

When selecting fields from XML column in SQL server I get no result and no error

xml

sql

sql-server

xquery