Pushing data to a JSON generated with json_encode - php

Question

In the following lines everything works if I don't try to push something to $dataJson.
$reponse = $bdd->query("SELECT Comp_Name,Comp_Email
FROM Company");
while ($donnees = $reponse->fetchAll(PDO::FETCH_ASSOC)) {
$dataJson = json_encode($donnees);
$dataJson.push({Col1:'Company Name',Col2:'Email'});
echo $dataJson;
};
I want to add a last object to the array of object generated by json_encode.
I may be missing something easy since every tips I found on internet failed to solve my issue.
Thanks

Answer 1

First, you don't need to call fetchAll() in a loop. It fetches all the results at once.
Next, you seem to be mixing Javascript syntax into your PHP. PHP doesn't use .shift() to add to an array, or {} as syntax for objects.
Next, you don't push onto the JSON, you push onto the array, then you encode the array as JSON.
If you want the column headings to be at the beginning of the array, you should use array_unshift(), not array_push().
So it should be:
$donnees = $response->fetchAll(PDO::FETCH_ASSOC);
array_unshift($donnees, array('Col1' => 'Company Name', 'Col2' => 'Email'));
$dataJson = json_encode($donnees);
echo $dataJson;

Answer 2

json_encode converts an array into a string. You can't push anything to strings, and you you try to concatenate, you will not end up with invalid json. do this instead.
$reponse = $bdd->query("SELECT Comp_Name,Comp_Email
FROM Company");
$data=array();
while ($donnees = $reponse->fetch(PDO::FETCH_ASSOC)) {
$data[]=$donnees;
};
echo json_encode($data);