PHP login with salt not working

Question

So I'm fairly new to PHP, but I'm trying to create a simple login system.

The problem that I have right now, is that for some reason the second SQL statement fails, or doesn't give anything back.

Here is the code that I use.

include 'dbConn.php';
if(isset($_POST['submit']))
{
   global $conn;
   $username = $_POST['username'];
   $password = $_POST['password'];

   $saltSql = "SELECT salt FROM users WHERE email = '$username'";
   $saltRes = $conn->query($saltSql);
   while($resRow = $saltRes->fetch_assoc()){
       $salt = $resRow['salt'];
   }
   $saltedHash = hash("sha512", ($password . $salt));
   $sql = "SELECT email, role, FROM users WHERE email = '$username' AND password = '$saltedHash'";
   $res = $conn->query($sql);

   if($res->num_rows == 1)
   {
     //Logged in succesfully
       echo "Logged in!";
   }
   else
   {
       //Something went wrong
       echo "Something went wrong";
   }
   $conn->close();
}

When I manually try to execute the second query in phpmyadmin I get this error: #1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'FROM users WHERE email = 'username' AND password = '5111109d49bc1' at line 1.

I would really appreciate some help with this.

Answer 1

Your problem seems to be this:

$sql = "SELECT email, role, FROM users WHERE email = '$username' AND password = '$saltedHash'"
--------------------------^

You have an extra comma , that causes crash your SQL query. Remove it and it works:

$sql = "SELECT email, role FROM users WHERE email = '$username' AND password = '$saltedHash'"