具有多个字段的 XML 模式键

Question

我有一个包含问题结构的 XML 文件格式：

<question id="q101">
  <text>Do you like the color red?</text>
  <answer>yes</answer>
  <answer>no</answer>
</question>
<question id="q102">
  <text>What is your favorite color?</text>
  <answer>red</answer>
  <answer>blue</answer>
  <answer>white</answer>
  <answer>yellow</answer>
</question>

我在同一个文件中也有来自多个用户的回复。

<user id="bob">
  <response questionIdRef="q101">yes</response>
  <response questionIdRef="q102">white</response>
</user>
<user id="jane">
  <response questionIdRef="q101">no</response>
  <response questionIdRef="q102">blue</response>
</user>

我已经在 xml 中为 questionId 定义了一个键和一个 keyref 元素：

<xsd:key name="questionId">
  <xsd:selector xpath=".//question" />
  <xsd:field xpath="@id" />
</xsd:key>
<xsd:keyref name="responseQuestionIdKeyRef" refer="questionId">
  <xsd:selector xpath=".//response" />
  <xsd:field xpath="@questionIdRef" />
</xsd:keyref>

我现在想做的是让架构验证用户对某个问题的响应值实际上是引用问题中提供的答案。我尝试使用以下密钥和 keyref 执行此操作，但它只能识别第一个答案，所有其他答案均未被识别为有效：

<xsd:key name="answerValue">
  <xsd:selector xpath=".//question" />
  <xsd:field xpath="@id" />
  <xsd:field xpath=".//answer/value" />
</xsd:key>
<xsd:keyref name="validAnswer" refer="answerValue">
  <xsd:selector xpath=".//response" />
  <xsd:field xpath="@questionIdRef" />
  <xsd:field xpath="." />
</xsd:keyref>

我得到的确切错误是：

“答案”字段最多需要一个值。

我应该注意我正在使用 C# XML 验证器。

为了完整起见，以下是我所指的完整架构和 xml 实例： 架构：

<?xml version="1.0" encoding="UTF-8"?>
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <xsd:element name="survey">
    <xsd:complexType>
      <xsd:sequence>
        <xsd:element name="user" maxOccurs="unbounded">
          <xsd:complexType>
            <xsd:sequence>
              <xsd:element name="response" maxOccurs="unbounded">
                <xsd:complexType>
                  <xsd:simpleContent>
                    <xsd:extension base="xsd:string">
                      <xsd:attribute name="questionIdRef" type="xsd:string" use="required" />
                    </xsd:extension>
                  </xsd:simpleContent>
                </xsd:complexType>
              </xsd:element>
            </xsd:sequence>
            <xsd:attribute name="id" type="xsd:string" use="required" />
          </xsd:complexType>
        </xsd:element>
        <xsd:element name="question" maxOccurs="unbounded">
          <xsd:complexType>
            <xsd:sequence>
              <xsd:element name="text" type="xsd:string" />
              <xsd:element name="answer" maxOccurs="unbounded" type="xsd:string"/>
            </xsd:sequence>
            <xsd:attribute name="id" type="xsd:string" use="required" />
          </xsd:complexType>
          <xsd:unique name="uniqueAnswer">
            <xsd:selector xpath=".//answer" />
            <xsd:field xpath="@value" />
          </xsd:unique>
        </xsd:element>
      </xsd:sequence>
    </xsd:complexType>
    <!--

    <xsd:key name="questionId">
      <xsd:selector xpath=".//question" />
      <xsd:field xpath="@id" />
    </xsd:key>
    <xsd:keyref name="responseQuestionIdKeyRef" refer="questionId">
      <xsd:selector xpath=".//response" />
      <xsd:field xpath="@questionIdRef" />
    </xsd:keyref>

    -->
    <xsd:key name="answerValue">
      <xsd:selector xpath=".//question" />
      <xsd:field xpath="@id" />
      <xsd:field xpath=".//answer" />
    </xsd:key>
    <xsd:keyref name="validAnswer" refer="answerValue">
      <xsd:selector xpath=".//response" />
      <xsd:field xpath="@questionIdRef" />
      <xsd:field xpath="." />
    </xsd:keyref>
    <xsd:unique name="uniqueUserId">
      <xsd:selector xpath=".//user" />
      <xsd:field xpath="@id" />
    </xsd:unique>
  </xsd:element>
</xsd:schema>

示例 XML 实例：

<?xml version="1.0" encoding="utf-8"?>
<survey>
  <user id="bob">
    <response questionIdRef="q101">yes</response>
    <response questionIdRef="q102">white</response>
  </user>
  <user id="jane">
    <response questionIdRef="q101">no</response>
    <response questionIdRef="q102">blue</response>
  </user>
  <question id="q101">
    <text>Do you like the color red?</text>
    <answer>yes</answer>
    <answer>no</answer>
  </question>
  <question id="q102">
    <text>What is your favorite color?</text>
    <answer>red</answer>
    <answer>blue</answer>
    <answer>white</answer>
    <answer>yellow</answer>
  </question>
</survey>

Answer 1

在您的架构中，使 answer 元素受枚举限制，以便在您的架构中看起来更像以下内容：

<xsd:simpleType name="answer">
    <xsd:restriction>
        <xsd:enumeration>red</xsd:enumeration>
        <xsd:enumeration>blue</xsd:enumeration>
        <xsd:enumeration>green</xsd:enumeration>
        <xsd:enumeration>yellow</xsd:enumeration>
    </xsd:restriction>
</xsd:simpleType>

枚举限制是给定元素的一组可接受的值。

Answer 2

好的，我发现这个问题 (XSD key/keyref: hierarchical key structure) 与我的问题有关。这个问题也没有可接受的答案。

这似乎是 XML Schema 技术的限制。我决定重新排序架构，将用户的回答放在问题之下。然后响应将指向用户。

以下是示例 XML 实例：

<?xml version="1.0" encoding="utf-8"?>
<survey>
  <user id="bob" />
  <user id="jane" />
  <question id="q101">
    <text>Do you like the color red?</text>
    <answer>yes</answer>
    <answer>no</answer>
    <response userIdRef="bob">yes</response>
    <response userIdRef="jane">no</response>
  </question>
  <question id="q102">
    <text>What is your favorite color?</text>
    <answer>red</answer>
    <answer>blue</answer>
    <answer>white</answer>
    <answer>yellow</answer>
    <response userIdRef="bob">white</response>
    <response userIdRef="jane">blue</response>
  </question>
</survey>

这是我使用的架构：

<?xml version="1.0" encoding="UTF-8"?>
<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <xsd:element name="survey">
    <xsd:complexType>
      <xsd:sequence>
        <xsd:element name="user" maxOccurs="unbounded">
          <xsd:complexType>
            <xsd:attribute name="id" type="xsd:string" use="required" />
          </xsd:complexType>
        </xsd:element>
        <xsd:element name="question" maxOccurs="unbounded">
          <xsd:complexType>
            <xsd:sequence>
              <xsd:element name="text" type="xsd:string" />
              <xsd:element name="answer" maxOccurs="unbounded" type="xsd:string"/>
              <xsd:element name="response" maxOccurs="unbounded">
                <xsd:complexType>
                  <xsd:simpleContent>
                    <xsd:extension base="xsd:string">
                      <xsd:attribute name="userIdRef" type="xsd:string" use="required" />
                    </xsd:extension>
                  </xsd:simpleContent>
                </xsd:complexType>
              </xsd:element>
            </xsd:sequence>
            <xsd:attribute name="id" type="xsd:string" use="required" />
          </xsd:complexType>
          <xsd:key name="validAnswerKey">
            <xsd:selector xpath=".//answer" />
            <xsd:field xpath="." />
          </xsd:key>
          <xsd:keyref name="responseValidAnswerKeyRef" refer="validAnswerKey">
            <xsd:selector xpath=".//response" />
            <xsd:field xpath="." />
          </xsd:keyref>
        </xsd:element>
      </xsd:sequence>
    </xsd:complexType>
    <xsd:key name="userIdKey">
      <xsd:selector xpath=".//user" />
      <xsd:field xpath="@id" />
    </xsd:key>
    <xsd:keyref name="userResponse" refer="userIdKey">
      <xsd:selector xpath=".//response" />
      <xsd:field xpath="@userIdRef" />
    </xsd:keyref>
  </xsd:element>
</xsd:schema>