Login only first user error

Question

Iam using the php 5.5 and pdo to create login code. the code is working fine but the only first user is loged in I don't know why? for example I have 5 user in my database table. when I login the first one then it goes to logedin but when I try to login the 2nd or 3rd one then it will show an error message which I set on incorrect data login. Below is my login code...

<?php
session_start();
include 'conn.php';
try
{
    $user = $_POST['user'];
    $pass = $_POST['pass'];
    $remember=$_POST['remember'];
        $smt=$conn->prepare("SELECT * FROM signup");
        $smt->execute();
        $result=$smt->fetch(PDO::FETCH_OBJ);
        $prev=$result->Password;
    $usr=$result->Username;

        if(password_verify($pass,$prev)& $user===$usr)
        {
        // Set username session variable
        $_SESSION['user'] = $user;
        // Jump to secured page
        header('location:index.php');
    }


    else
    {

        header('location:signin.php');
        $_SESSION['login']="Incorrect username or password";
    }

    if($remember)
    {
        setcookie('remember-me',$user,time()+3600000);
        setcookie('remember-pass',$pass,time()+3600000);
        header('location:index.php');

    }
    else
    {
        setcookie('remember-me',$user,false);
        setcookie('remember-pass',$pass,false);


    }

}
catch(PDOException $e)
{
    throw new PDOException($e);
}

?>

Thanks in advance...

Answer 1

You are missing a WHERE CLAUSE :

SELECT * FROM signup WHERE Username = :user

adjust your code to the following:

$smt=$conn->prepare("SELECT * FROM signup WHERE Username =:user");
$smt->execute(array(':user'=>$user));

Answer 2

Please update your code with below code

<?php
session_start();
include 'conn.php';
try
{
    $user = $_POST['user'];
    $pass = $_POST['pass'];
    $remember=$_POST['remember'];
        $smt=$conn->prepare("SELECT * FROM signup WHERE username = '".$user."' AND password = '".$pass."' ");
        $smt->execute();
        $result=$smt->fetch(PDO::FETCH_OBJ);
        $prev=$result->Password;
    $usr=$result->Username;

        if(password_verify($pass,$prev)& $user===$usr)
        {
        // Set username session variable
        $_SESSION['user'] = $user;
        // Jump to secured page
        header('location:index.php');
    }


    else
    {

        header('location:signin.php');
        $_SESSION['login']="Incorrect username or password";
    }

    if($remember)
    {
        setcookie('remember-me',$user,time()+3600000);
        setcookie('remember-pass',$pass,time()+3600000);
        header('location:index.php');

    }
    else
    {
        setcookie('remember-me',$user,false);
        setcookie('remember-pass',$pass,false);


    }

}
catch(PDOException $e)
{
    throw new PDOException($e);
}

?>