PHP MySQL insert statement won't insert data into my database

Question

I am trying to insert some data into my database with this code:

        $username = $_SESSION['user'];
        $naslov = $_POST['naslov'];//name
        $geslo = $_POST['geslo'];//password
        $vsebina = $_POST['vsebina'];//description

        if (trim($_POST['naslov'])=="" || $_POST['geslo']=="" || $_POST['vsebina']==""){
        $status = "<div class='alert-danger'>Fields are empty</div>";
           }
     else{
        $link = open_database_connection();

        echo $username;
        echo $naslov;
        echo $geslo;
        echo $vsebina;

        $sql = "INSERT INTO projects (name, password, description, username) VALUES ('$naslov','$geslo','$vsebina','$username')";
         mysqli_query($link, $sql);

        close_database_connection($link);
        $status = "<div class='alert-success'>Vic je bil dodan.</div>";
        }

The echo show the values i am putting into the forms, the SQL does not show any errors it just doesn't insert the values into the table.

Answer 1

check if form method is POST if its not then change the code to

     $username = $_SESSION['user'];
    $naslov = $_GET['naslov'];//name
    $geslo = $_GET['geslo'];//password
    $vsebina = $_GET['vsebina'];//description

    if (trim($_GET['naslov'])=="" || $_GET['geslo']=="" || $_GET['vsebina']==""){
    $status = "<div class='alert-danger'>Fields are empty</div>";
       }
 else{
    $link = open_database_connection();

    echo $username;
    echo $naslov;
    echo $geslo;
    echo $vsebina;

    $sql = "INSERT INTO projects (name, password, description, username) VALUES ('$naslov','$geslo','$vsebina','$username')";
     mysqli_query($link, $sql);

    close_database_connection($link);
    $status = "<div class='alert-success'>Vic je bil dodan.</div>";
    }