<?xml version="1.0" encoding="utf-8"?>
<info>
  <data>
    <field1>test1_1</field1>
    <field2> 12 </field2>
    <field3>test1_3</field3>
  </data>
  
  <data>
    <field1>test2_1</field1>
    <field2> 22 </field2>
    <field3>test2_3</field3>
  </data>
</info>

<?xml version="1.0" encoding="utf-8"?>
<xs:schema attributeFormDefault="unqualified" elementFormDefault="qualified" xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:complexType name="Papa" abstract="true">
    <xs:all>                                            <!-- VS ругается на этот тег: "'all' is not the only particle in a group, or is being used as an extention."-->
      <xs:element name="field1" type="xs:string" />
      <xs:element name="field2" type="xs:int" />
    </xs:all>
  </xs:complexType>

  <xs:complexType name="ChildOne">
    <xs:complexContent>
      <xs:extension base="Papa">
        <xs:all>
          <xs:element name="field3" type="xs:string" />
        </xs:all>
      </xs:extension>
    </xs:complexContent> 
  </xs:complexType>

  <xs:element name="info">
    <xs:complexType>
      <xs:sequence maxOccurs="unbounded">
        <xs:element name ="data" type="ChildOne" />
      </xs:sequence>
    </xs:complexType>
  </xs:element>    
</xs:schema>