<set_clause xmlns="http://www.sqlparser.com/xml/ansi2003">
  <multiple_column_assignment>{1,1}</multiple_column_assignment>
  <set_target_equals_update_source>{1,1}</set_target_equals_update_source>
</set_clause>

<xs:element name="set_clause">
  <xs:complexType>
    <xs:choice>
      <xs:element ref="multiple_column_assignment"/>
      <xs:element name="set_target_equals_update_source">
        <xs:complexType>
          <xs:sequence>
            <xs:element ref="set_target"/>
            <xs:element ref="equals_operator"/>
            <xs:element ref="update_source"/>
          </xs:sequence>
        </xs:complexType>
      </xs:element>
    </xs:choice>
  </xs:complexType>
</xs:element>

<set_target_equals_update_source xmlns="http://www.sqlparser.com/xml/ansi2003">
  <set_target>{1,1}</set_target>
  <equals_operator>{1,1}</equals_operator>
  <update_source>{1,1}</update_source>
</set_target_equals_update_source>

<xs:element name="set_target_equals_update_source">
  <xs:complexType>
    <xs:sequence>
      <xs:element ref="set_target"/>
      <xs:element ref="equals_operator"/>
      <xs:element ref="update_source"/>
    </xs:sequence>
  </xs:complexType>
</xs:element>