User log
Id
Email
Password

User
Id
User_id fk id reference userlog(id)
Name
Surname

<?php
session_start();

if (isset($_SESSION['usuario'])) {
    header('Location: index.php');
}

$errores = '';

if ($_SERVER['REQUEST_METHOD'] == 'POST') {
    $email = filter_var(strtolower($_POST['email']), FILTER_SANITIZE_STRING);
    $password = $_POST['password'];
    $password = hash('sha512', $password);

    try {
        $conexion = new PDO('mysql:host=localhost;dbname=DATABASE, 'USER', 'PASS');
    } catch (PDOException $e) {
        echo "Error:" . $e->getMessage();;
    }

    $statement = $conexion->prepare('
        SELECT * FROM userlog WHERE email = :email AND password = :password'
    );
    $statement->execute(array(
        ':email' => $email,
        ':password' => $password
    ));

    $resultado = $statement->fetch();
    if ($resultado !== false) {
        $_SESSION['usuario'] = $resultado;
        header('Location: index.php');
    } else {
        $errores .= '<li>Datos Incorrectos</li>';
    }
}

$servername = "localhost";
$username = "yourUser";
$password = "yourPass";
$dbname = "youtDB";

try {
$conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);
$sql = "INSERT INTO Userlog (email, password)
VALUES ('some_email@example.com', 'some_safe_password')";

$conn->exec($sql);
$last_id = $conn->lastInsertId();
$userSql = "INSERT INTO Userlog (userId, name, lastName) VALUES ($last_id, 'some_name', 'some_lastName')";
$conn->exec($userSql);


}
catch(PDOException $e)
    {
    echo $sql . "<br>" . $e->getMessage();
    }

$sql = "INSERT INTO users (Userlog, Id, Email, Password)
        VALUES ('".$_POST["Userlog"]."','".$_POST["Id"]."','".$_POST["Email"].",'".$_POST["Password"]."')";