lo script php che sto usando è questo

<?php
$con=mysqli_connect("localhost","root","password", "domotica");
// Check connection
if (mysqli_connect_errno())
{
echo "Failed to connect to MySQL: " . mysqli_connect_error();
}


$result = mysqli_query($con,"SELECT DATE(data_time), MAX(temperatura) FROM sensore_esterno GROUP BY DATE(data_time)");






echo "<table border='1' bordercolor='#FF0000'>
<tr>
<th>DATA E ORA</th>
<th>TEMPERATURA</th>
</tr>";


while($row = mysqli_fetch_array($result))
{
echo "<tr>";
echo "<td>" . $row['data_time'] . "</td>";
echo "<td>" . $row['temperatura'] . " °C" . "</td>";
echo "</tr>";
}
echo "</table>";


mysqli_close($con);
?>