SESSION PHP LOGIN

Question

I’m having problems creating a Session in php. It is as if she simply "did not create", when I will validate if she exists with isset it is as if she did not exist.

I don’t know what I’m missing, here comes the validation code:

<?php

include_once("conexao.php");

$usuario_adm = $_POST['usuario_adm'];
$senha_adm = $_POST['senha_adm'];

$sql = "select  * from adm where usuario='$usuario_adm' and senha='$senha_adm'";
$res = mysqli_query($conexao,$sql);
$linhas = mysqli_num_rows($res);

if ($linhas == ''){
    header("Location: soldaforte.php");
}

else {

    while ($dados=mysqli_fetch_assoc($res)){

        session_start();
        $_SESSION['adm_usu'] = $dados['nome_usu'];
        header("Location: empresa.php");
    }
}

mysqli_close($conexao);


?>

<?php

session_start();

if (!isset($_SESSION['adm_usu'])){
    header("Location: soldaforte.php");
}
?>

Answer 1

I think the mistake is this:

if ($linhas == ''){

Exchange for:

if ($linhas == 0){

Because mysqli_num_rows always returns int and no empty string, in the case when no results will return zero (0)

---

Now if the fault continues make a simple test, swap all session_start() for session_start() or die('A sessão não pode ser iniciada');, thus:

<?php

include_once("conexao.php") or die('A sessão não pode ser iniciada');

$usuario_adm = $_POST['usuario_adm'];
$senha_adm = $_POST['senha_adm'];

$sql = "select  * from adm where usuario='$usuario_adm' and senha='$senha_adm'";
$res = mysqli_query($conexao,$sql);
$linhas = mysqli_num_rows($res);

if ($linhas == ''){
    header("Location: soldaforte.php");
}

else {

    while ($dados=mysqli_fetch_assoc($res)){

        session_start();
        $_SESSION['adm_usu'] = $dados['nome_usu'];
        header("Location: empresa.php");
    }
}

mysqli_close($conexao);

?>

The other file

<?php

session_start() or die('A sessão não pode ser iniciada');

if (!isset($_SESSION['adm_usu'])){
    header("Location: soldaforte.php");
}
?>

I say this because it is likely to have some "white space above" even invisible in the text/script editor, if the message appears:

Session cannot be started

Is that in fact the session does not start and probably the errors are turned off on your server, may be the level of error_reporting or the display_errors be off

In this case if you are in localhost connect all errors in your php.ini, if you know how to edit, look for that line (this is to set the error capture level for the log):

error_reporting=

Change her value to

error_reporting=E_ALL

And then look for the line display_errors=, change the value to:

display_errors=On

I recommend you read Why use error_reporting with display_errors and display_startup_errors? to understand about each PHP flag and log configuration

I restarted your local server, either apache or Nginx, whatever it is, you need to restart it completely, if you can’t just log out your user and log back in and then start your server.

Then after this test the scripts, it is likely that session_start() will issue a Warning thus:

Warning: session_start() [Function.Session-start]: Cannot send Session cache Limiter - headers already sent (output Started at

So it really is a spacing error, you may have saved the scripts as UTF-8 with B.O.M., to resolve read this:

• Error - "Cannot Modify header information - headers already sent" (the most voted answer is excellent, read calmly that you will never again go through this problem, understanding the technologies is more important than getting ready solutions :) )

Now pay attention, if the error is this:

Warning: Unknown: open(..., O_RDWR) failed: Permission denied (13) in Unknown on line 0

So the problem is much more serious, the folder that gets the session files is inaccessible to PHP (or Apache/Ngnix user etc), so this can help:

• /a/206614/3635

But it is an alternative solution, although where saving these sessions is the choice of who configures the server, as long as it does not save in public places, such as ./www or ./public_html

Another similar error that occurred to me including in "professional" hosting was this:

Warning: Unknown(): write failed: No space left on device (28) in Unknown on line 0

• The configured directory (in the case /tmp) is not writable.
• Directory does not allow current user access (server may have user access - main, but directory only has root access).
• It could be a directory that doesn’t exist.

Basically the same solution: /a/51161/3635