在另一个用户注册时,如何检查mysql数据库中是否已存在电子邮件或用户名,因此我可以停止注册过程,并可能建议新用户在数据库中不存在另一个2/3新用户名.

所以我尝试解决这个问题,我只能得到一种检查数据库中是否已经存在电子邮件的方法,同时我需要一种可以检查数据库中的用户名和电子邮件并分别打印$error的方法.我的意思是,如果电子邮件存在而用户名不存在,则只会打印错误电子邮件,并且用户名也相同.

我希望有人能理解我.

if(isset($_POST['register'])) {

$username = $_POST['username'];

$full_name = ucwords($_POST['full_name']);

$email = $_POST['email'];

$password = trim($_POST['password']);

$time = time();

$age = $_POST['age'];

$gender = $_POST['gender'];

// Geolocation

$longitude = $_SESSION['longitude'];

$latitude = $_SESSION['latitude'];

$geo_info = $geo->getInfo($latitude,$longitude);

$city = $geo_info['geonames'][0]['name'];

$country = $geo_info['geonames'][0]['countryName'];

$check_d = $db->query("SELECT username, email from users WHERE username = '$username' OR email = '$email'");

$check_d = $check_d->num_rows;

if($check_d == 0) {

$db->query("INSERT INTO users (profile_picture,username,full_name,email,password,registered,credits,age,gender,ip,country,city,longitude,latitude) VALUES ('default_avatar.png','$username','$full_name','$email','".$auth->hashPassword($password)."','$time','100','$age','$gender','$ip','".$country."','".$city."','".$longitude."','".$latitude."')");

setcookie('justRegistered', 'true', time()+6);

setcookie('mm-email',$email,time()+60*60*24*30,'/');

header('Location: '.$domain.'/people');

}

else { $error = 'Username or password already exist, Try Another';

}

}

if($auth->isLogged()) {

$first_name = $system->getFirstName($_SESSION['full_name']);

$logged_in_user = header('Location: '.$domain.'/people');

}

$users = $db->query("SELECT * FROM users ORDER BY RAND() LIMIT 7");

?>