how to auto login after submitting sign up form in php? - mysqli

Question

i am using php mysqli coding,i create sign up form and login form both are working separately but now i want to provide login after sign up successfully.
this is my sign up code:
{
# insert data into mysql database
$sql = "INSERT INTO `users` (`id`, `username`, `password`, `phone`, `email`)
VALUES (NULL, '{$name}', '{$password}', '{$phone}', '{$email}')";
$query="SELECT * FROM users WHERE email= '$email'";
if ($mysqli->query($sql)) {
$reslt=$mysqli->query($query);
$usr=$reslt->fetch_array();
$_SESSION[user_email]=$usr['email'];
redirect_to("profile.php?email={$_SESSION['user_email']}");
} else {
echo "<p>MySQL error no {$mysqli->errno} : {$mysqli->error}</p>";
exit();
}
}
I tried this way but insertion operation is doing properly but page is refreshing and not redirecting to "profile.php" which is i mentioned in code

Answer 1

first of all, I would suggest that for for a login you check both email and password. Your query should look like:
$query="SELECT * FROM users WHERE email= '$email' and password = '$password'";
Next, if ($mysqli->query($sql)) { just verifies if the sql operation has succeeded. If the user and password are wrong, the sql will succeed but you will have no rows returned.
What you have to do is to verify that you have only 1 row returned by the query. In fact your code should more look like:
...
// check how many users correspond to the query
// ! the result will be an arry
$users = $reslt->fetch_array();
// if I have only one user, login is successfull
if(count($users) === 1) {
$_SESSION['user_email'] = $users[0]['email'];
} else {
// login failed
}
...