Variable is empty

Question

I am trying to show data from the database in my textbox. But when I start the script I am getting no results. I tested the script in different ways and i figured out that the variable: $product1 is empty. Does anybody know how I can fix this?

index.php

<?php
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "database";

// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
     die("Connection failed: " . $conn->connect_error);
} 

$sql = "SELECT * FROM forms";
$result = $conn->query($sql);

if ($result->num_rows > 0) {
     echo "<select class='form-control select2' id='product1' name='product1' onChange='getPrice(this.value)' style='width: 100%;'>";
     echo "<option selected disabled hidden value=''></option>";
     // output data of each row
     while($row = $result->fetch_assoc()) {
                      echo "<option value='" . $row["id"]. "'>" . $row["name"]. "</option>";
     }                   
echo "</select>";
} else {
     echo "0 results";
}

$conn->close();

?>
<html>
<body>
<!-- Your text input -->
<input id="product_name" type="text">

    <script src="http://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<script>
    function getPrice() {

        // getting the selected id in combo
        var selectedItem = jQuery('.product1 option:selected').val();

        // Do an Ajax request to retrieve the product price
    jQuery.ajax({
        url: 'get.php',
        method: 'POST',
        data: 'id=' + selectedItem,
        success: function(response){
            // and put the price in text field
            jQuery('#product_name').val(response);  
        },
        error: function (request, status, error) {
            alert(request.responseText);
        },
    }); 
    }
    </script>
    </body>
    </html>

get.php

<?php
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "database";

// Create connection
$conn = new mysqli($servername, $username, $password, $dbname) ;
// Check connection
if ($conn->connect_error) 
    {
    die('Connection failed: ' . $conn->connect_error) ;
    } 
else 
    {
    $product1 = filter_input(INPUT_POST, 'id', FILTER_SANITIZE_NUMBER_INT) ;

    $query = 'SELECT price FROM forms WHERE id=" . $product1 . " ' ;

    $res = mysqli_query($conn, $query) ;
if (mysqli_num_rows($res) > 0) 
{
    $result = mysqli_fetch_assoc($res) ;
    echo $result['price'];
}else{
    echo 'no results';
}

    }
?>

Ramon Bakker · Accepted Answer · 2016-02-21 01:28:48Z

1

Change

var selectedItem = jQuery('.product1 option:selected').val();

To

var selectedItem = jQuery('#product1 option:selected').val();

You are selecting a class with name product1, but you set only an ID with this name. Id's are specified with # and classes with .

Update on your script, because you used getPrice(this.value);

<script>
function getPrice(selectedItem) {

    // Do an Ajax request to retrieve the product price
jQuery.ajax({
    url: 'get.php',
    method: 'POST',
    data: 'id=' + selectedItem,
    success: function(response){
        // and put the price in text field
        jQuery('#product_name').val(response);  
    },
    error: function (request, status, error) {
        alert(request.responseText);
    },
}); 
}
</script>

TIP: Did you know that you can use jQuery.ajax and jQuery('selector') also like this: $.ajax and $('selector') :-)

edited Feb 21, 2016 at 1:28

answered Feb 21, 2016 at 1:23

Ramon Bakker

1,08512 silver badges24 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Nikolas Meyer · Accepted Answer · 2016-02-21 01:20:17Z

0

You have not a form tag in your HTML. The default form Method is GET.

In Your get.php you try to get a POST Variable with filter_input The function filter_input returns null if the Variable is not set.

Two possible solutions: 1. Add a form to your html with method="post" 2. Change your php code to search for a GET variable

answered Feb 21, 2016 at 1:20

Nikolas Meyer

1162 bronze badges

Collectives™ on Stack Overflow

Variable is empty

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related