PHP PDO Select query returns double values - php

Question

For my inhome temparature sensor i'm using a raspberry pi with php, sqlite, PDO, and HTML.
I've create a table in sqlite
Using
BEGIN;
CREATE TABLE waarden (datum TEXT, tijd TEXT, zone TEXT, lucht REAL, temperatuur REAL);
COMMIT;
My rpi with DHT22 records everything fine so no i've created a webpage accessing the data via AJAX using the following php.file
<?php
function datumConversie($datum){
$delen = explode('/',$datum,3);
$geconverteerd = $delen[2].$delen[0].$delen[1];
return $geconverteerd;
}
ini_set('display_errors', 'On');
error_reporting(E_ALL | E_STRICT);
$db = new PDO("sqlite:/home/pi/sensor.db");
$result_array = array();
$date = $_POST["datepicker"];
$waarde = datumConversie($date);
$tijd="";
$temperatuur="";
$query = "SELECT datum, tijd, zone,lucht, temperatuur FROM waarden WHERE datum = $waarde";
$result = $db->query($query);
foreach($result as $row)
{
array_push($result_array, $row);
}
echo json_encode($result_array);
$db = null;
?>
The problem is that when I look in the browser response it seems that values are returned twice. Once with their appropriate field-name and once with their column index. (0 being datum, 1 being tijd etc). See below
{"datum":"20170601","0":"20170601","tijd":"00:01","1":"00:01","zone":"kelder","2":"kelder","lucht":"53.0","3":"53.0","temperatuur":"24.3","4":"24.3"},
{"datum":"20170601","0":"20170601","tijd":"00:06","1":"00:06","zone":"kelder","2":"kelder","lucht":"53.1","3":"53.1","temperatuur":"24.3","4":"24.3"},
{"datum":"20170601","0":"20170601","tijd":"00:11","1":"00:11","zone":"kelder","2":"kelder","lucht":"53.1","3":"53.1","temperatuur":"24.2","4":"24.2"},
How can I avoid this. I've tried several conversions which can work in the end but that is just patching some flaw without addressing the cause?
Any suggestions

Answer 1

Set the default fetch mode like so
$db->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_OBJ);
Or
$db->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_ASSOC);
before running the fetch
$db->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_ASSOC);
foreach($result as $row) {
array_push($result_array, $row);
}
Or replace with a one liners using fetchAll() and use prepared and parameterized statements as well to mitigate against SQL Injection Attack
$query = "SELECT datum, tijd, zone,lucht, temperatuur
FROM waarden
WHERE datum = :datum";
$result->prepare($query);
$result->execute([':datum'=>$waarde]);
$result_array = $result->fetchAll(PDO::FETCH_ASSOC);
The parameter to fetchAll(PDO::FETCH_ASSOC) controls how results will be returned.

Answer 2

Try this sample code...
$sth = $db->prepare("SELECT datum, tijd, zone,lucht, temperatuur FROM waarden WHERE datum = :datum");
$sth->execute(array('datum' => $waarde));
$result = $sth->fetchAll(PDO::FETCH_ASSOC);
echo '<pre>';
print_r($result);
echo '</pre>';