Collapse Table when nothing is generated - php

Question

With this PHP code I generate a table. with content from the database. Now I want to collapse it if it didn't generate any content.
It's only a part of the table otherwise there would be to much code. The rest of the table is the same.
<table class="table">
<tr class="day">
<th>
<?php
$j = 0;
thisDayIs($weekDays[$j]);
echo "<br>";
echo $weekDays[$j];
$j++;
?>
</th>
<?php
$datum = $weekDays[$j];
$parameters = array(':date'=>$datum,
':aid'=>$id);
$sth = $pdo->prepare("SELECT DISTINCT opdrachten.KRITISCHE_DATUM, opdrachten.PLANNINGS_DATUM, opdrachten.OPDRACHTID, onderzoekactiviteiten.A_UITVOERDER
FROM opdrachten
INNER JOIN onderzoekactiviteiten
ON opdrachten.OPDRACHTID=onderzoekactiviteiten.OPDRACHTID
WHERE PLANNINGS_DATUM = :date
AND A_UITVOERDER = :aid");
$sth->execute($parameters);
while ($row = $sth->fetch())
{
$cutKritDate = substr($row['KRITISCHE_DATUM'], 0, 10);
$cutPlanDate = substr($row['PLANNINGS_DATUM'], 0, 10);
echo "<td>Krit= " . $cutKritDate . "<br>";
echo "Plan= " . $cutPlanDate . "<br>";
echo "Opdracht= " . $row['OPDRACHTID'] . "</td>";
}
?>
</tr>
<tr class="day">
<th>
<?php
thisDayIs($weekDays[$j]);
echo "<br>";
echo $weekDays[$j];
$j++;
?>
</th>
<?php
$datum = $weekDays[$j];
$parameters = array(':date'=>$datum,
':aid'=>$id);
$sth = $pdo->prepare("SELECT DISTINCT opdrachten.KRITISCHE_DATUM, opdrachten.PLANNINGS_DATUM, opdrachten.OPDRACHTID, onderzoekactiviteiten.A_UITVOERDER
FROM opdrachten
INNER JOIN onderzoekactiviteiten
ON opdrachten.OPDRACHTID=onderzoekactiviteiten.OPDRACHTID
WHERE PLANNINGS_DATUM = :date
AND A_UITVOERDER = :aid");
$sth->execute($parameters);
while ($row = $sth->fetch())
{
$cutKritDate = substr($row['KRITISCHE_DATUM'], 0, 10);
$cutPlanDate = substr($row['PLANNINGS_DATUM'], 0, 10);
echo "<td>Krit= " . $cutKritDate . "<br>";
echo "Plan= " . $cutPlanDate . "<br>";
echo "Opdracht= " . $row['OPDRACHTID'] . "</td>";
}
?>
</tr>
</table>
I've tried something with jquery but it didn't work at all.
jquery:
$('.day').click(function()
{
$(this).nextUntil('tr.day').slideToggle(1000);
});
I have 5 rows and no idea what to do i have been struggeling a lot with this and can't find a solution.
Thanks in advance!!