solr/contrib/dataimporthandler/src/test-files/dih/solr/collection1/conf/single-entity-data-config.xml

<dataConfig>
  <dataSource type="MockDataSource"/>
  <document>
    <entity name="x" query="select * from x">
      <field column="id" />
      <field column="desc" />
    </entity>
  </document>
</dataConfig>