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Question

如何在给定的xml上执行以下查询：

如果（task1 = cde＆amp;＆amp; task2 = abc）我会得到id = XYZ-987
if（（task1 = abc＆amp;＆amp; task2 = efg）|| task5 = nop）我会得到id = ABC-123，XYZ-987，RST-567

XML：

<node1>
<node2>
    <node3>
        <id>ABC-123</id>
        <condition>
            <task name="task1" operation="and" value="abc" />
            <task name="task2" operation="and" value="efg" />
            <task name="task3" operation="and" value="hij" />
            <task name="task4" operation="or" value="klm" />
            <task name="task5" operation="and" value="nop" />
            <task name="task6" value="uvw" />
        </condition>
    </node3>
    <node3>
        <id>XYZ-987</id>
        <condition>
            <task name="task1" operation="and" value="cde" />
            <task name="task2" operation="and" value="abc" />
            <task name="task5" operation="and" value="nop" />
        </condition>
    </node3>
    <node3>
        <id>RST-567</id>
        <condition>
            <task name="task1" operation="and" value="abc" />
            <task name="task2" operation="and" value="efg" />
            <task name="task8" operation="and" value="jkl" />
            <task name="task9" operation="and" value="rst" />
            <task name="task10" value="xyz" />
        </condition>
    </node3>
    <node3>
        <id>PQR-345</id>
        <condition>
            <task name="task1" operation="and" value="ijk" />
            <task name="task2" operation="and" value="klm" />
            <task name="task8" operation="and" value="jkl" />
            <task name="task9" operation="and" value="rst" />
        </condition>
    </node3>
</node2>
</node1>

我尝试了以下规则，但结果是空的

String expression = "/node1/node2/node3/id[following-sibling::condition/task[(@name='task1' and @value='cde') and (@name='task2' and @value='abc')]]"

我从上面得到了上述表达 How to parse XML using XPATH

上述两种情况的表达方式是什么？

Answer 1

你的xpath不起作用的原因是你的谓词[(@name='task1' and @value='cde') and (@name='task2' and @value='abc')]在同一个任务节点上执行，如果@name = 'task1'那么@name可以永远不会= 'task2'。

相反，您应该创建将在/检查所有相关节点的谓词，如下所示：

1

如果（task1 = cde＆amp;＆amp; task2 = abc）我会得到id = XYZ-987

/node1/node2/node3[condition/task[@name='task1' and @value='cde'] and condition/task[@name='task2' and @value='abc']]/id

2

如果（（task1 = abc＆amp;＆amp; task2 = efg）|| task5 = nop）我会得到id = ABC-123，XYZ-987，RST-567

/node1/node2/node3[condition/task[@name='task1' and @value='abc'] and condition/task[@name='task2' and @value='efg'] or condition/task[@name='task5' and @value='nop']]/id

如果需要，可以包括括号，但在布尔运算中，and参数始终在or参数之前进行求值，因此在这种情况下它们是不必要的： /node1/node2/node3[(condition/task[@name='task1' and @value='abc'] and condition/task[@name='task2' and @value='efg']) or condition/task[@name='task5' and @value='nop']]/id

XPATH执行复杂查询

1 个答案:

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