将数据库数据检索到JSON - 移动登录表单

Question

Im creating Mobile App using Phonegap that first need to login. if login success It will retrieve the data to JSON.

This is the PHP page that connects to mobile site and retrieve the data.

<?php
$con = mysqli_connect($mysql_hostname, $mysql_user, $mysql_password,$mysql_database);
if (mysqli_connect_errno()) {
  echo "Failed to connect to MySQL: " . mysqli_connect_error();
}else{
    //echo 'ok';
}

if(isset($_POST['username']) && isset($_POST['password'])){
    $username = $_POST['username'];
    $password = $_POST['password'];
}

$sql = "SELECT * FROM member WHERE username = '$username' AND password = '$password'";
$result = mysqli_query($con,$sql);

if (!$result) {
  //die('Error: ' . mysqli_error($con));
  $data = array('status'=>'failure','Error: ' . mysqli_error($con));
}else {
    //$result = mysqli_query($con,$sql);
    $row = mysqli_fetch_array($result);
    $details = array(
                        'id'=>$row['id'],
                        'username'=>$row['username'],
                        'email'=>$row['email'],
                        'password'=>$row['password'],
                        'repassword'=>$row['repassword'],
                    );
    $data = array('status'=>'success','data'=>$details);
}
echo json_encode($data);
mysqli_close($con);
?>

but it doesnt work properly. I'm following my lecturer Code. but i think he has missed something

here my HTML content

<script>
    function login(){

var uName=$("#loginID").val();
var pwd=$("#pwdID").val();

$.post("http://boost.meximas.com/mobile/verifying.php", { username: uName, password: pwd },
   function(json){
console.log(json);
var obj = jQuery.parseJSON(json );
console.log(obj.status);
if(obj.login == "success"){
alert("success");
}
else
alert("Incorrect user name or password");
});
}
    </script>


<div data-role="content">
                <Table>
    <tr><td>Login</td>
    <td><input class="fld" id="loginID" name="txtNum1" type="text" value="" /></td></tr>
    <tr><td>Password</td>
    <td><input class="fld" id="pwdID" name="txtNum1" type="text" value="" /></td></tr>

</Table>
    <a class="ui-button" data-role="button" onClick="login();" data-transition="slide" id="flipid" >Login</a>
        </div>

Answer 1

There are a few issues I can see off the bat:

1. You are testing if isset($_POST['username']) && isset($_POST['password']) but, you are not actually catching the case where they are not set, and you are continuing to execute the code with null/empty values.
2. the SQL injection issue I mentioned in my comment to your question, you should never let this code be visible on a public facing website.

Without more detail, I am unable to say if the issue lies with the HTML, the PHP or the JavaScript.

I would change change the if/else when testing the username/password to return something like: $data = array('status'=>'failure','Error' => 'Invalid username/password'); when the username/password is not set.

I hope this helps.