Check Function

Discussion in 'PHP' started by K0307277, May 7, 2007.

  1. #1
    Hi guys,
    I am quite new to PHP and MySQL. I have created a form for a booking form and i want to check the username is valid against one in the database. If it is not valid i would like an error message to come up. Does anyone know the syntax for this?:) :)
     
    K0307277, May 7, 2007 IP
  2. Wyla

    Wyla Well-Known Member

    Messages:
    924
    Likes Received:
    14
    Best Answers:
    0
    Trophy Points:
    140
    #2
    $username = $_POST['user']; //Gets username from the form
    $query = mysql_query("SELECT * FROM `tablename` WHERE `user` = $username"); //Searches table "tablename" for user
    $num = mysql_affected_rows($query);//Counts the amount of rows returned/affected
    if($num != 0 ){ //if # of rows affected is not equal to 0
     echo "user found!"; //user found
    }else{ //otherwise
     echo "user NOT found!"; //user not found
    }
    PHP:
     
    Wyla, May 7, 2007 IP
  3. gibex

    gibex Active Member

    Messages:
    1,060
    Likes Received:
    21
    Best Answers:
    0
    Trophy Points:
    95
    #3
    small issue: sql injection

    use this code instead
    
    $query = mysql_query("SELECT * FROM `tablename` WHERE `user` = '".mysql_real_escape_string(stripslashes($username))."');
    
    PHP:
    Another issue
    In your case (SELECT command) instead of mysql_affected_rows, use mysql_num_rows($query);
     
    gibex, May 10, 2007 IP