使用ajax检查是否存在电子邮件[关闭]

Question

Basically, I want to check if the email exists in the DB automatically. The function will not work when connection.php & mysqli queries was inserted.

HTML:

<input type="email" name="email" class="formEmail">

JS:

  $( document ).ready(function() {
    $('.formEmail').on('change', function() {
        //ajax request
        $.ajax({
            url: "queries/checkEmail.php",
            data: {
                'email' : $('.formEmail').val()
            },
            dataType: 'json',
            success: function(data) {
                if(date == true) {
                    alert('Email exists!');
                }
                else {
                    alert('Email doesnt!');
                }
            },
            error: function(data){
                //error
            }
        });
    });
  });

PHP:

require_once("../connection.php");

$userEmail = $_GET['email'];

$checkEmail=mysqli_query($con, "SELECT email from accounts WHERE email='$userEmail'");

if (mysqli_num_rows($checkEmail) == 1) {
  $response = true;
} else {
  $response = false;
}

echo json_encode($response);

Answer 1

You made a small mistake in getting the response in the if condition in the success block of ajax call function.

Rewrite date to data in if condition

$( document ).ready(function() {
    $('.formEmail').on('change', function() {
        //ajax request
        $.ajax({
            url: "queries/checkEmail.php",
            data: {
                'email' : $('.formEmail').val()
            },
            dataType: 'json',
            success: function(data) {
                if(data == true) {
                    alert('Email exists!');
                }
                else {
                    alert('Email doesnt!');
                }
            },
            error: function(data){
                //error
            }
        });
    });
});