从 SQL 服务器中的 XML 读取子节点及其父属性

Question

我有一个XML类似于这个结构。

<Root>
<id>a2bh5</id>
<Student ID="123">
    <Name>abc<Name>
    <course>ETL<course>
    <Scores>
        <Score>
            <Subject>SSIS<subject>
            <grade>B<grade>
        </score>
        <Score>
            <Subject>Informatica<subject>
            <grade>C<grade>
        </score>
    </Scores>
</Student>
<Student ID="456">
    <Name>xyz<Name>
    <course>ETL<course>
    <Scores>
        <Score>
            <Subject>Pentaho<subject>
            <grade>F<grade>
        </score>
        <Score>
            <Subject>Datastage<subject>
            <grade>A<grade>
        </score>
    </Scores>
</Student>
</Root>

我想在 SQL 服务器中使用 Xquery 从子节点（分数）及其父属性（Id）获取详细信息。

所有主题的查询结果预计如下所示。请帮忙。

Student_Id subject grade
========================
123     SSIS        B

Answer 1

首先，您需要修复 XML。您的 Name、course、Subject 和 grade 元素没有正确的结束标记。此外，元素名称在 XML 中区分大小写； Subject 和 subject 不是一回事。

完成后，您可以使用 nodes() method 将 XML 分成行，然后提取所需的数据。像这样：

declare @test xml = 
    '<Root>
    <id>a2bh5</id>
    <Student ID="123">
        <Name>abc</Name>
        <course>ETL</course>
        <Scores>
            <Score>
                <Subject>SSIS</Subject>
                <grade>B</grade>
            </Score>
            <Score>
                <Subject>Informatica</Subject>
                <grade>C</grade>
            </Score>
        </Scores>
    </Student>
    <Student ID="456">
        <Name>xyz</Name>
        <course>ETL</course>
        <Scores>
            <Score>
                <Subject>Pentaho</Subject>
                <grade>F</grade>
            </Score>
            <Score>
                <Subject>Datastage</Subject>
                <grade>A</grade>
            </Score>
        </Scores>
    </Student>
    </Root>';

select
    [Student ID] = N.x.value('(../../@ID)[1]', 'bigint'),
    [Subject] = N.x.value('(./Subject)[1]', 'varchar(64)'),
    [Grade] = N.x.value('(./grade)[1]', 'char(1)')
from
    @test.nodes('/Root/Student/Scores/Score') N(x)

结果：

Student ID   Subject       Grade
---------------------------------
123          SSIS          B
123          Informatica   C
456          Pentaho       F
456          Datastage     A

Answer 2

清理样本 XML 并正确关闭所有标签后，试试这个：

DECLARE @input XML = '<Root>
<id>a2bh5</id>
<Student ID="123">
    <Name>abc</Name>
    <course>ETL</course>
    <Scores>
        <Score>
            <Subject>SSIS</Subject>
            <grade>B</grade>
        </Score>
        <Score>
            <Subject>Informatica</Subject>
            <grade>C</grade>
        </Score>
    </Scores>
</Student>
<Student ID="456">
    <Name>xyz</Name>
    <course>ETL</course>
    <Scores>
        <Score>
            <Subject>Pentaho</Subject>
            <grade>F</grade>
        </Score>
        <Score>
            <Subject>Datastage</Subject>
            <grade>A</grade>
        </Score>
    </Scores>
</Student>
</Root>'

SELECT
    StudentID = XStudents.value('@ID', 'int'),
    Course = XStudents.value('(course)[1]', 'varchar(50)'),
    Subject = XScore.value('(Subject)[1]', 'varchar(50)'),
    Grade = XScore.value('(grade)[1]', 'varchar(10)')
FROM
    @Input.nodes('/Root/Student') AS XT1(XStudents)
CROSS APPLY
    XStudents.nodes('Scores/Score') AS XT2(XScore)

这给出了输出：

从 SQL 服务器中的 XML 读取子节点及其父属性

Read child node along with its parent attribute from XML in SQL server

sql-server

xquery-sql