I wrote a php in the process after treatment such as :
$db = JFactory::getDBO();
$db->setQuery("SELECT rs.`SubmissionId` FROM mbss_rsform_submissions AS rs , mbss_rsform_submission_values AS rsv1 WHERE
rs.`SubmissionId`=rsv1.`SubmissionId`
AND rs.`UserId`='".JFactory::getUser()->id."'
AND rs.`FormId`=45
AND rsv1.`FieldName`='info_nom'
AND rsv1.`Fieldvalue`='"{info_nom:value}"'
AND exists (
select true from mbss_rsform_submission_values AS rsv2 where rsv1.`SubmissionId`= rsv2.`SubmissionId`
AND `FieldName` = 'info_prenom'
AND `Fieldvalue` = '"{info_prenom:value}"'

)
group by rs.`SubmissionId` ORDER BY rs.`SubmissionId` DESC LIMIT 2");
$oldSubId = '';
if(count($db->loadColumn()) == 2){
$oldSubId = $db->loadColumn()[1];
}
if(!empty($oldSubId)){
$db->setQuery("DELETE rs,rsv FROM #__rsform_submissions AS rs ,#__rsform_submission_values AS rsv WHERE
rs.`SubmissionId`=rsv.`SubmissionId` AND rs.`SubmissionId`='".$oldSubId."'");
$db->execute();
}

What is the correct writing to retrieve the {info_nom:value} of the recorded files ? such like in the following condition => AND rsv1.`Fieldvalue`='"{info_nom:value}"'