Incorrect response from Ajax and php

Question

Hello please I don't know what I am doing wrong here. I am trying to use ajax for a login page. The ajax is working but the successful response is not from the file I specified. I need it to read response from the login_validate.php but I am getting response from the dbconnect.php which shouldn't work like that.

this is the index.php which is the ajax page

jQuery(document).ready(function(){
 jQuery(".login").submit(function(e){
    e.preventDefault();
    var formData = jQuery(this).serialize();
    $.ajax({
        type:"POST",
        url:"login_validate.php",
        data:formData,
        success: function(response){
            /** alert (response);
         }, error: function(jqXHR, textStatus, errorThrown){
                alert('error');
         } **/       
            if(response == "True")
            {
                //alert('Yes');
                //$.jGrowl("Loading File Please Wait......", { sticky: true });
                $.jGrowl("Welcome... Redirecting", { header: 'Login Successful' });
                var delay = 3000;
                setTimeout((function(){ window.location = 'welcome.php'  }), delay);

            }else{
                //alert('No');
                $.jGrowl("Invalid Login Details", { header: 'Access Denied' });
            }
        }
    });
    return false;
});

});

this is the dbconnect.php

<?php
// connect to database
$hostname = "localhost";
$username = "root";
$password = "";
$dbname = "cbt2";


 $conn = new mysqli($hostname, $username, $password, $dbname);
 // check connection
 if ($conn->connect_error) {
    die ('Error connecting to database' . $conn->connect_error);
 } else {
    echo "Connection Successful";
 }
 ?>

this is the login_validate.php

<?php
require 'admin/dbconnect.php';
require 'admin/core.php';

if(loggedin())
{
    header('location:welcome.php');
}
if (isset($_POST['loginbtn'])){
    $name=$_POST['username'];
    $pass= $_POST['password'];

    $qry="SELECT * FROM student WHERE username='$name' AND password='$pass' LIMIT 1";
    $qrycheck=$conn->query($qry);
    if ($qrycheck->num_rows > 0){
        while($fetch = $qrycheck->fetch_assoc()){
            $class=$fetch['class'];
            $fullname=$fetch['fullname'];
            $username=$fetch['username'];
            $dept=$fetch['dept'];
            $id=$fetch['id'];

            $_SESSION['stdid']=$id;
            $_SESSION['user']=$username;
            $_SESSION['name']=$fullname;
            $_SESSION['class']=$class;
            $_SESSION['dept']=$dept;

        }
        echo "True";
    } else {
        echo "False";
    }
}
?>

So the successful response I am getting is the echo 'Connection Successful' and it should be echo 'True'

Your script is wide open to [SQL Injection Attack](http://stackoverflow.com/questions/60174/how-can-i-prevent-sql-injection-in-php) Even [if you are escaping inputs, its not safe!](http://stackoverflow.com/questions/5741187/sql-injection-that-gets-around-mysql-real-escape-string) Use [prepared parameterized statements](http://php.net/manual/en/mysqli.quickstart.prepared-statements.php) in either the `MYSQLI_` or `PDO` API's — RiggsFolly, Jul 10 '18 at 13:51

godot · Accepted Answer · 2018-07-13T10:28:02.627

remove your else statement from dbconnect.php

<?php
// connect to database
$hostname = "localhost";
$username = "root";
$password = "";
$dbname = "cbt2";




$conn = new mysqli($hostname, $username, $password, $dbname);
 // check connection
 if ($conn->connect_error) {
    die ('Error connecting to database' . $conn->connect_error);
 } 
 ?>

When connection is successful your dbconnect.php echoes "Connection successful" which is read first by ajax, and it is not what are you waiting for. It is not even recommended to echo or log every single time when connection to database is successful.

UPDATE:

also update your login_validate.php:

<?php
require 'admin/dbconnect.php';
require 'admin/core.php';


if (isset($_POST['username'], $_POST['password'])){
    $name=$_POST['username'];
    $pass= $_POST['password'];

    $qry="SELECT * FROM student WHERE username='$name' AND password='$pass' LIMIT 1";
    $qrycheck=$conn->query($qry);
    if ($qrycheck->num_rows > 0){
        while($fetch = $qrycheck->fetch_assoc()){
            $class=$fetch['class'];
            $fullname=$fetch['fullname'];
            $username=$fetch['username'];
            $dept=$fetch['dept'];
            $id=$fetch['id'];

            $_SESSION['stdid']=$id;
            $_SESSION['user']=$username;
            $_SESSION['name']=$fullname;
            $_SESSION['class']=$class;
            $_SESSION['dept']=$dept;

        }
        echo "True";
    } else {
        echo "False";
    }
}
?>

when you're calling php file from ajax, there you don't need to redirect somewhere, it should just return something. Also I think it is redundant to check if $_POST['loginbtn'] is set or not.

Thanks for your answer. After removing the echo from dbconnect.php, no response from the login_validate again. I am still getting invalid login details even after entering correct details — Amjos.com, Jul 10 '18 at 14:47
Hello, please I am still not getting this done. Please advise on what else to do — Amjos.com, Jul 11 '18 at 14:45
After removing the echo in the connect.php, I am not getting any response from ajax again. Not giving any response. — Amjos.com, Jul 13 '18 at 10:18
Thank you very much. The problem is with the dbconnect directory. Now working perfectly — Amjos.com, Jul 13 '18 at 10:45

score 1 · Answer 2 · answered Jul 10 '18 at 13:50

The reply to the AJAX call will be everything that is output from your PHP script(s)

So you need to remove the echo "Connection Successful"; from here

<?php
// connect to database
$hostname = "localhost";
$username = "root";
$password = "";
$dbname = "cbt2";


 $conn = new mysqli($hostname, $username, $password, $dbname);
 // check connection
 if ($conn->connect_error) {
    die ('Error connecting to database' . $conn->connect_error);
 //} else {
    //echo "Connection Successful";
 }
 ?>

Incorrect response from Ajax and php

2 Answers2