所以我有这个XML数据库
<uni>
<!-- SUBJECTS ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -->
<subjects>
<subject code="XYZ111">
<title>Java for housewives</title>
<credits>6</credits>
<laboratories>
<laboratory num="lab1">
<date>12-MAR-2009</date>
<topics>
<topic>variables</topic>
<topic>constants</topic>
</topics>
<description>Declarations of variables and constants</description>
</laboratory>
<laboratory num="lab2">
<date>12-APR-2009</date>
<topics>
<topic>expressions</topic>
</topics>
<description>Types of expressions</description>
</laboratory>
<laboratory num="lab3">
<date>12-MAY-2009</date>
<topics>
<topic>conditionals</topic>
<topic>loops</topic>
</topics>
<description>Control statements</description>
</laboratory>
</laboratories>
</subject>
<subject code="XYZ235">
<title>Database systems for politicians</title>
<credits>6</credits>
<laboratories>
<laboratory num="lab1">
<date>10-JAN-2001</date>
<topics>
<topic>classes</topic>
<topic>associations</topic>
<topic>properties</topic>
</topics>
<description>Conceptual modeling</description>
</laboratory>
<laboratory num="lab2">
<date>10-JAN-2002</date>
<topics>
<topic>relational tables</topic>
<topic>primary keys</topic>
<topic>foreign keys</topic>
</topics>
<description>Relational data model</description>
</laboratory>
</laboratories>
</subject>
<subject code="XYZ987">
<title>Ethics for car dealers</title>
<credits>6</credits>
</subject>
<subject code="XYZ101">
<title>Programming for mathematicians</title>
<credits>6000</credits>
<laboratories>
<laboratory num="lab1">
<date>10-JAN-2002</date>
<topics>
<topic>abstract algebra</topic>
</topics>
<description>Hilbert spaces of programming languages</description>
</laboratory>
<laboratory num="lab2">
<date>13-MAY-2002</date>
<topics>
<topic>topology</topic>
</topics>
<description>Theory of homothopy</description>
</laboratory>
</laboratories>
</subject>
<subject code="ZZZ777">
<title>Cooking</title>
<credits>5</credits>
<laboratories/>
</subject>
<subject code="ZZZ778">
<title>Dancing</title>
<credits>5</credits>
<laboratories/>
</subject>
<subject code="ABC123">
<title>General theory of everything</title>
<credits>4</credits>
<laboratories>
<laboratory num="lab1">
<date>20-JAN-2012</date>
<topics>
<topic>space</topic>
</topics>
<description>Nothing really interesting</description>
</laboratory>
</laboratories>
</subject>
</subjects>
<!-- ENROLMENTS ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -->
<enrolments>
<enrolment snum="d2345" code="ABC123">
<date>12-DEC-2011</date>
<status>dropped</status>
<time>20</time>
<IP>16.23.234.002</IP>
<lab-enrolments>
<laboratory num="lab1"/>
</lab-enrolments>
</enrolment>
<enrolment snum="d2346" code="ABC123">
<date>12-DEC-2011</date>
<status>dropped</status>
<time>2</time>
<IP>16.23.234.003</IP>
<lab-enrolments>
<laboratory num="lab1"/>
</lab-enrolments>
</enrolment>
<enrolment snum="d2347" code="ABC123">
<date>12-DEC-2011</date>
<status>dropped</status>
<time>10</time>
<IP>16.23.234.003</IP>
</enrolment>
<enrolment snum="d2348" code="ABC123">
<date>12-DEC-2011</date>
<status>dropped</status>
<time>20</time>
<IP>16.23.234.025</IP>
</enrolment>
<enrolment snum="d6767" code="ABC123">
<date>13-DEC-2011</date>
<status>valid</status>
<time>5</time>
<IP>16.23.234.202</IP>
</enrolment>
<enrolment snum="d2345" code="ZZZ778">
<date>14-DEC-2007</date>
<status>valid</status>
<time>10</time>
<IP>16.23.234.402</IP>
</enrolment>
<enrolment snum="d6767" code="ZZZ777">
<date>12-SEP-2005</date>
<status>valid</status>
<time>15</time>
<IP>16.23.234.202</IP>
</enrolment>
<enrolment snum="d2330" code="XYZ101">
<date>01-JAN-2002</date>
<status>valid</status>
<time>3</time>
<IP>16.23.234.203</IP>
<lab-enrolments>
<laboratory num="lab1"/>
<laboratory num="lab2"/>
</lab-enrolments>
</enrolment>
<enrolment snum="d2349" code="XYZ101">
<date>01-JAN-2002</date>
<status>valid</status>
<time>7</time>
<IP>16.23.234.202</IP>
<lab-enrolments>
<laboratory num="lab1"/>
<laboratory num="lab2"/>
</lab-enrolments>
</enrolment>
<enrolment snum="d2341" code="XYZ101">
<date>01-JAN-2002</date>
<status>valid</status>
<time>6</time>
<IP>16.23.234.201</IP>
<lab-enrolments>
<laboratory num="lab1"/>
</lab-enrolments>
</enrolment>
<enrolment snum="d6767" code="XYZ101">
<date>01-JAN-2002</date>
<status>provisional</status>
<time>5</time>
<IP>16.23.234.002</IP>
</enrolment>
<enrolment snum="d6767" code="XYZ235">
<date>31-DEC-2000</date>
<status>provisional</status>
<time>30</time>
<IP>16.23.234.602</IP>
</enrolment>
</enrolments>
</uni>
我试图找到包含抽象代数实验室主题的标题。到目前为止，这是我能提出的最佳答案，但它找不到匹配项：/ //uni/subjects/subject/laboratories/laboratory/topics/topic[text()="abstract algebra"]
答案 0 :(得分：3)
你在找这个：
//subject[laboratories/laboratory/topics/topic[.="abstract algebra"]]/title
答案 1 :(得分：2)
您可以尝试这种方式：
//subject[laboratories/laboratory/topics/topic="abstract algebra"]/title