如何在SQL Server 2012中从xml获取值

Question

我有大约9000行的表，我需要从每一行中获取一些值，还需要从xml中命名值。

表格栏： Eaid ， Created ， AttachedApplication

XML：

<NamedApplication xmlns:xs="http://www.w3.org/2001/XMLSchema-instance">
    <mainpart>
        <firstname>John</firstname>
        <surname>Smith</surname>
        <extras />
    </mainpart>
</NamedApplication>

我无法在表格中得到结果。 姓名和姓氏为NULL

Answer 1

尝试这个：

SELECT
    EAId,
    FirstName = xc.value('(firstname)[1]', 'varchar(100)'),
    Surname = xc.value('(surname)[1]', 'varchar(100)')
FROM
    dbo.YourTableName
CROSS APPLY
    AttachedApplication.nodes('/NamedApplication/mainpart') AS XT(XC)

这将“枚举”您的表，返回EAID列，它将“进入” XML并从该XML内获取<firstname>和<surname>节点，并将它们显示为输出中的单独列。

更新：如果运行此示例，该示例使用表变量-可以工作并返回值吗？

DECLARE @Table TABLE (Eaid INT, Created DATE, AttachedApplication XML)

INSERT INTO @Table (Eaid, Created, AttachedApplication)
VALUES (1, GETDATE(),
    '<NamedApplication xmlns:xs="http://www.w3.org/2001/XMLSchema-instance">
    <mainpart>
        <firstname>John</firstname>
        <surname>Smith</surname>
        <extras />
    </mainpart>
</NamedApplication>')

SELECT
    EAId,
    FirstName = xc.value('(firstname)[1]', 'varchar(100)'),
    Surname = xc.value('(surname)[1]', 'varchar(100)')
FROM
    @Table
CROSS APPLY
    AttachedApplication.nodes('/NamedApplication/mainpart') AS XT(XC)