php mysql NOT NULL

[spillage]

So after dabling with a flat file I am now trying to use a database. By using eregi I have sorted out  writing to the file if a field is incorect or blank.

when using mysql I thought using NOT NULL would do the same but if the field is blank it still writes to the database. This is my first time trying to use mysql with php and not sure where I

am going wrong so any help would be appreciated.

 

@ $fp= fopen ("$DOCUMENT_ROOT/rcfriend.txt",'a+');


      echo "<p>Your email is: ".$cust.'</p></br>';
      


   if (!eregi('^[[:alnum:]][a-z0-9_\.\-]*@[a-z0-9\.\-]+\.[a-z]{2,4}$',
            stripslashes(trim($friend))))
            {
			echo "<p>Please enter your friends valid email below:</p></br>";

		}

    else

           {
   	           echo "<p>Thank you.</p>";
               echo "<p>Your friends email has been submitted.</p>";
           echo "<p>Please submit another email or close your browser.</p></br>";
           fwrite ($fp,$output, strlen($output));
               fclose($fp);
           }
           
$friend= addslashes($friend);
$con=mysql_connect("localhost","root", "");
if (!con)
{
die('could not connect: '.mysql_error());
}

mysql_select_db("promoemail", $con);

mysql_query("INSERT INTO email  
VALUES ('$id', '$cust.', '$friend' NOT NULL, '$time')");

mysql_close ($con);

?>

 

Thanks

Spill

[dezkit]

friendly bump 4 u

[DarkWater]

@ $fp= fopen ("$DOCUMENT_ROOT/rcfriend.txt",'a+');


      echo "<p>Your email is: ".$cust.'</p></br>';
      


   if (!eregi('^[[:alnum:]][a-z0-9_\.\-]*@[a-z0-9\.\-]+\.[a-z]{2,4}$',
            stripslashes(trim($friend))))
            {
			echo "<p>Please enter your friends valid email below:</p></br>";
                               $friend = NULL;

		}

    else

           {
   	           echo "<p>Thank you.</p>";
               echo "<p>Your friends email has been submitted.</p>";
           echo "<p>Please submit another email or close your browser.</p></br>";
           fwrite ($fp,$output, strlen($output));
               fclose($fp);
           }
           
$friend= addslashes($friend);
$con=mysql_connect("localhost","root", "");
if (!con)
{
die('could not connect: '.mysql_error());
}

mysql_select_db("promoemail", $con);
if (!is_null($friend)) {
mysql_query("INSERT INTO email  
VALUES ('$id', '$cust.', '$friend', '$time')");
}

mysql_close ($con);

 

Notice how I set friend = NULL if they didn't enter a valid friend.