The following example queries and orders: 

<ac:SqlDataSource>
   <ac:jdbcDriver>com.mysql.jdbc.Driver</ac:jdbcDriver>
   <ac:jdbcUrl>jdbc:mysql://localhost:7188/col2010ac?user=root</ac:jdbcUrl>
   <ac:sqlQuery><![CDATA[
      SELECT record_id, parent_id, label FROM table ORDER BY record_id
   ]]></ac:sqlQuery>
</ac:SqlDataSource>

In the object rule empty record separator should be used:

<ac:objectRules rdf:parseType="Collection">
   <ac:ObjectRule rdf:about="recordRule">
   <ac:recordSeparator></ac:recordSeparator>
   <ac:recordIdentifier>record_id</ac:recordIdentifier>
   <ac:recordInformalIdentifier>label</ac:recordInformalIdentifier>
   <ac:propertyRules>
    ...
   </ac:propertyRules>
</ac:ObjectRule>