How to return database query into ajax? - php

Question

I want to check if a user has favourited an item but I'm unsure how to return the result of a database query to ajax.
I will show different html depending on the result.
Php
$query = "SELECT itemID from favourites WHERE userid = '" . $user. "'";
$result = mysql_query($query);
echo json_encode($result);
Jquery
$.ajax({
url: "inc/functions.php",
type: "POST",
data: {--result--},
success: function () {
// if result found in database
$('favourite').hide();
// if result not found
$('favourite').show();
}
});
I can't figure out how to display $result in the jquery code.
Any help much appreciated.

Answer 1

$result in this case is a PHP object representing a result.
You will have to use a fetch() method in order to extract the result before sending it back to your JS.
See this link. There's a list of all fetch-family method right above the comments.
Also, you will need to make a connection with you database beforehand using mysqli_connect (or mysql_connect in your case).
As stated in the comments, you should however use mysqli* functions family instead of mysql*.

Answer 2

Thanks to the comments for info regarding mysqli. I updated the code and solved the ajax part.
For anyone else stuck, I got it working like this:
PHP
require ("../../connection.php");
$sql = "SELECT * FROM favourites WHERE userID = ? AND itemID = ?";
$user = $_POST['userID'];
$item = $_POST['itemID'];
$statement = $db->prepare($sql);
if($statement === false) {
trigger_error('Wrong SQL: ' . $sql . ' Error: ' . $db->error, E_USER_ERROR);
}
$statement->bind_param('ii',$user,$item);
$statement->execute();
$statement->bind_result($user,$item);
while($statement->fetch()){
echo 1;
}
$statement->close();
Jquery
$.ajax({
url: "inc/userList.php",
data: userList,
type: "POST",
success: function (result) {
if (result == 1){
$('#addItem').css('display', 'none');
$('#removeItem').css('display', 'inline-block');
} else {
$('#addItem').css('display', 'inline-block');
$('#removeItem').css('display', 'none');
}
}
});