php - Hide empty td if count value is empty in datatables -

i have script works hidden null values in mysql db, empty values count them...so how can hide values too?

<table class="table table-bordered table-striped table-condensed bootstrap-datatable datatable" >     <thead>         <tr>             <th>diagn&oacute;sticos</th>             <th class="center sorting_desc">casos vistos</th>                                         </tr>     </thead>        <tbody>         <?              $sql = $conn->prepare("select diagnostico, count(diagnostico) ( select diagnostico diagnostico diagnosticon id_doctor = $id_doctor union select diagnostico1 diagnostico diagnosticon union select diagnostico2 diagnostico diagnosticon union select diagnostico3 diagnostico diagnosticon) t group t.diagnostico order count(diagnostico) desc ");             $sql->execute();             while($row = $sql->fetch(pdo::fetch_assoc)) {             echo "<tr>\n";                                               echo "<td>";                 if (!empty($row["diagnostico"]))             {              echo $row["diagnostico"]."</td>\n"; }              echo "<td>";                 if (!empty($row["count(diagnostico)"]))             {             echo $row["count(diagnostico)"]."</td>\n";             echo "</tr>\n";  }             }         ?>      </tbody> </table> 

replace

count(diagnostico) 

with

count(case when diagnostico = '' null else diagnostico end)