PHP/Mysql authentication script getting NULL result from query -

i working on test project, trying learn more php , mysql , not. have decided build authentication engine test website having issues query.

basically, if run...

select * users name="tester" , passwd=md5('pass'); 

from mysql console, get...

+--------+---------------+----------------------------------+ | name   | email         | passwd                           | +--------+---------------+----------------------------------+ | tester | test@test.com | 1a1dc91c907325c69271ddf0c944bc72 | +--------+---------------+----------------------------------+ 1 row in set (0.00 sec) 

however,when issue same query (at least think same) php code (see below) appear getting null result, authentication fails.

<?php     include 'db_connect.php';      $username = $_post['username'];     $passwd = $_post['passwd'];      // protect mysql injection (more detail mysql injection)     //$username = stripslashes($username);     //$passwd = stripslashes($passwd);     //$username = mysql_real_escape_string($username);     //$passwd = mysql_real_escape_string($passwd);      //encrypted password     $secpasswd = md5($passwd);      $sql="select * users name='$username' , passwd = $secpasswd";      $result=mysql_query($dbconnect,$sql);     var_dump($result);      // mysql_num_row counting table row     $count=mysql_num_rows($result);     //var_dump($count);      // if result matched $myusername , $mypassword, table row must 1 row     if($count==1){          // register $myusername, $mypassword , redirect file "login_success.php"         session_register("username");         session_register("passwd");          header("location:login_success.php");         }     else {         echo "wrong username or password";         }     ob_end_flush(); ?> 

there s lot of problems code.

• you sql query format wrong
• you don't fetch values query result
• your hashing weak
• you aren't using prepared statements
• you using outdated session functions

here how have

<?php include 'db_connect.php';  //encrypted password $secpasswd = sha512($_post['passwd'].$_post['username']);  $sql = "select * users name = ? , passwd = ?"; $stm = $pdo->prepare($sql); $stm->execute(array($_post['username'], $secpasswd)); $row = $stm->fetch();  if($row){     $_session["username"] = $row[username];     header("location:login_success.php");     exit; } else {     echo "wrong username or password"; } 

note code using pdo database interaction