我有一个这样的xml结构:
<Quiz xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="file:/C:/Users/Snedden27/Documents/RIT/Knowledge%20representation/xml/schema/Quizzer%20Project/quiz.xsd" QID="q1" CourseID="IST 01"> //here QID is the ID of the quiz
<QuizTaker RITeMAIL="" Name="Type in your Name here"/>
<Instruction>Thisis nicequiz</Instruction>
<Questions Objective="Yes" TotalMarks="10">
<Question QNumber="1" QIDref="q1"> //I am trying to reference QID here
<Q>WHat is your name?</Q>
<Option OptionNum="1" OptionValue="Leon"/>
<Option OptionNum="2" OptionValue="Snedden"/>
<Answer>1</Answer>
</Question>
<Question QIDref="q1" QNumber="2" > //I am trying to reference QID here i.e ID of quiz
<Q>Whats your dog name?</Q>
<Answer></Answer>
</Question>
</Questions>
</Quiz>
但由于某种原因,我收到一个错误:key qKEy 的值不够,这是我的架构:
<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" >
<xs:element name="Quiz">
<xs:complexType>
<xs:sequence>
<xs:element name="QuizTaker">
<xs:complexType>
<xs:attributeGroup ref="student_Att_Group"></xs:attributeGroup>
</xs:complexType>
</xs:element>
<xs:element name="Instruction" type="xs:string" />
<xs:element name="Questions" >
<xs:complexType>
<xs:sequence>
<xs:element name="Question" minOccurs="1" maxOccurs="unbounded">
<xs:complexType>
<xs:sequence>
<xs:element name="Q" type="xs:string"></xs:element>
<xs:element name="Option" minOccurs="0" maxOccurs="unbounded">
<xs:complexType>
<xs:attribute name="OptionNum" use="required" type="xs:nonNegativeInteger" ></xs:attribute>
<xs:attribute name="OptionValue" use="required" type="xs:string"></xs:attribute>
</xs:complexType>
</xs:element>
<xs:element name="Answer" type="xs:string"></xs:element>
</xs:sequence>
<xs:attributeGroup ref="Q_details_Att_Group"></xs:attributeGroup>
</xs:complexType>
</xs:element>
</xs:sequence>
<xs:attributeGroup ref="question_Att_Group"></xs:attributeGroup>
<xs:attribute name="TotalMarks" use="required" type="xs:nonNegativeInteger"></xs:attribute>
</xs:complexType>
</xs:element>
</xs:sequence>
<xs:attributeGroup ref="Quiz_details_Att_Group" />
</xs:complexType>
<xs:unique name="optionId">
<xs:selector xpath="./Questions/Question/Option"/>
<xs:field xpath="@OptionNum"/>
</xs:unique>
<!----------------- gave the entire schema but this is what matters I guess,so highlighting---------------------------->
<xs:key name="QId">
<xs:selector xpath="." />
<xs:field xpath="@QID" />
</xs:key>
<xs:key name="QKey">
<xs:selector xpath="./Questions/Question"/>
<xs:field xpath="@Qno"/>
<xs:field xpath="@QIDref"/>
</xs:key>
<xs:keyref name="QKeyRef" refer="QId">
<xs:selector xpath="./Questions/Question"/>
<xs:field xpath="@QIDref" />
</xs:keyref>
</xs:element>
<xs:attributeGroup name="Q_details_Att_Group">
<xs:attribute name="QNumber" use="required" ></xs:attribute>
<xs:attribute name="QIDref" use="required"></xs:attribute>
</xs:attributeGroup>
<xs:attributeGroup name="Quiz_details_Att_Group">
<xs:attribute name="QID" use="required" type="xs:ID" ></xs:attribute>
<xs:attribute name="CourseID" use="required"></xs:attribute>
</xs:attributeGroup>
<xs:attributeGroup name="student_Att_Group">
<xs:attribute name="Name" use="optional" default="Type in your Name here"></xs:attribute>
<xs:attribute name="RITeMAIL" use="required" ></xs:attribute>
</xs:attributeGroup>
<xs:attributeGroup name="question_Att_Group">
<xs:attribute name="Objective" use="required" >
<xs:simpleType>
<xs:restriction base="xs:string">
<xs:enumeration value="Yes"></xs:enumeration>
<xs:enumeration value="No"></xs:enumeration>
</xs:restriction>
</xs:simpleType>
</xs:attribute>
<xs:attribute name="Marks" type="xs:nonNegativeInteger"/>
</xs:attributeGroup>
</xs:schema>