如何使用XSD / XML Schema约束XML元素以包含有限长度的字符串内容？

Question

I have an XSD Schema where I am trying to implement some basic validation.

The provided code is as follows:

<xs:complexType>
    <xs:sequence>
          <xs:element name="PersonID" type="xs:string" minOccurs="1" maxOccurs="1"/>
          <xs:element name="AgreementID" type="xs:string" minOccurs="1" maxOccurs="1"/>

I want to add some validation so the element PersonID can only have a maximum length of 8 characters. The agreementID to have 7 and so on.

What is the easiest way to implement this? I have tried looking at length but it doesn't seem to be validating when building the file.

Thanks

Answer 1

<?xml version="1.0" encoding="utf-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
           version="1.0">

  <xs:simpleType name="PersonIDType">
    <xs:restriction base="xs:string">
      <xs:maxLength value="8" />
    </xs:restriction>
  </xs:simpleType>

  <xs:simpleType name="AgreementIDType">
    <xs:restriction base="xs:string">
      <xs:maxLength value="7" />
    </xs:restriction>
  </xs:simpleType>

  <xs:complexType name="TestType">
    <xs:sequence>
      <xs:element name="PersonID" type="PersonIDType" minOccurs="1" maxOccurs="1"/>
      <xs:element name="AgreementID" type="AgreementIDType" minOccurs="1" maxOccurs="1"/>
    </xs:sequence>
  </xs:complexType>

</xs:schema>