I'm trying to send data to my local DB server but I keep getting 400 Bad request error when I try to send it.

var studentEmail = "[email protected]";
            var dataString = '&questionNumber='+ temp + '&answer='+ value + '&email='+ studentEmail;


            $.ajax({
            type: "POST",
            dataType:'json',
            url: "js/dbcon.php",
            data: JSON.stringify(dataString),
            processData: false,
            contentType: "application/json; charset=utf-8"
            });

and this is the php file

<?php
$connection = mysql_connect("127.0.0.1", "root", "root"); // Establishing Connection with Server..
$db = mysql_select_db("db", $connection); // Selecting Database
//Fetching Values from URL
$questionNumber=$_POST['questionNumber'];
$answer=$_POST['answer'];
$email=$_POST['email'];
//Insert query
$query = mysql_query("INSERT INTO answers (questionNumber,studentAnswer,studentEmail) VALUES ($questionNumber,$answer,$email)");
echo "succesfully posted";
mysql_close($connection); // Connection Closed
?>

can anyone see what I'm doing wrong?

Thanks in advance!

I'm trying to send data to my local DB server but I keep getting 400 Bad request error when I try to send it.

var studentEmail = "[email protected]";
            var dataString = '&questionNumber='+ temp + '&answer='+ value + '&email='+ studentEmail;


            $.ajax({
            type: "POST",
            dataType:'json',
            url: "js/dbcon.php",
            data: JSON.stringify(dataString),
            processData: false,
            contentType: "application/json; charset=utf-8"
            });

and this is the php file

<?php
$connection = mysql_connect("127.0.0.1", "root", "root"); // Establishing Connection with Server..
$db = mysql_select_db("db", $connection); // Selecting Database
//Fetching Values from URL
$questionNumber=$_POST['questionNumber'];
$answer=$_POST['answer'];
$email=$_POST['email'];
//Insert query
$query = mysql_query("INSERT INTO answers (questionNumber,studentAnswer,studentEmail) VALUES ($questionNumber,$answer,$email)");
echo "succesfully posted";
mysql_close($connection); // Connection Closed
?>

can anyone see what I'm doing wrong?

Thanks in advance!

• javascript
• php
• jquery
• mysql
• ajax

• ps if I change POST to GET it works but doesnt insert the data to my DB – faradji Commented Feb 23, 2017 at 12:42
• You're sure that dbcon.php is in the js folder? Seems rather strange... – chishiki Commented Feb 23, 2017 at 12:44
• You must escape the string @ is not valid inside a URL. – evolutionxbox Commented Feb 23, 2017 at 12:44
• This is not good: You are not sending key-value pairs, so you will not get any data from $_POST on the server, you are not sending back json so your ajax call will never finish successfully, you have an sql injection problem and you use a deprecated mysql api. – jeroen Commented Feb 23, 2017 at 12:46
• I made sure the php file is in the js folder – faradji Commented Feb 23, 2017 at 12:47

4 Answers 4

JSON.stringify() method is used to turn a javascript object into json string.

So dataString variable must be a javascript object:

var data ={questionNumber:temp ,answer: value ,email:studentEmail};

AJAX

$.ajax({
    type: "POST",
    dataType:'json',
    url: "js/dbcon.php",
    data: JSON.stringify(data),
    processData: false,
    contentType: "application/json; charset=utf-8"
});

if you change the post to get you have to replace $_POST with $_GET into your php file.

There is an easier way to pass data that will work correctly for both POST and GET requests

var studentEmail = "[email protected]";
$.ajax({
        type: "POST",
        dataType:'json',
        url: "js/dbcon.php",
        data: {questionNumber:temp, answer:value, email: studentEmail},
        processData: false,

});

Now jQuery does all the hard work and converts the object full of data to whatever format is required for a POST or GET request

You can send the ajax request this way:

var studentEmail = "[email protected]";
            $.ajax({
            type: "POST",
            dataType:'json',
            url: "js/dbcon.php",
            data: ({'questionNumber':temp,'answer':value, 'email':studentEmail }),
            processData: false,
            contentType: "application/json; charset=utf-8"
            });

Also the PHP file needs to return a json string as well.

echo "succesfully posted";

is no valid json answer.

Return something like this:

$arr = array('success' => true, 'answer' => "succesfully posted");

echo json_encode($arr);

See also here: http://php/manual/de/function.json-encode.php

You should validate the input data, before inserting into the database.