Если вам нужна базовая система входа на сайт, попробуйте это.
Форма входа:
<form id="login-form" class="loginform" action='include/login.inc.php' method='POST'>
<input id="login-email" type='text' name='email' placeholder='Email'>
<input id="login-pwd" type='password' name='pwd' placeholder='Password'>
</form>
А затем добавьте php-код.
Login.inc.php:
<?php
session_start();
include '../dbh.php';
$email = $_POST['email'];
$pwd = $_POST['pwd'];
$sql = "SELECT * FROM user WHERE email= ? ";
$stmt = mysqli_prepare($conn, $sql);
mysqli_stmt_bind_param($stmt, 's', $email);
mysqli_stmt_execute($stmt);
$result = mysqli_stmt_get_result($stmt);
$row = mysqli_fetch_assoc($result);
if(password_verify($pwd, $row['pwd'])) {
$_SESSION['id'] = $row['id'];
$userID = $row['id'];
header("Location: ../profile.php?id=$userID");
exit();
} else {
header("Location: ../login-error-page.php");
exit();
}
?>