inlog-PROCEDURE

De query IN PHP:
    SELECT COUNT(*)
      FROM somewhere
     WHERE username = '$username'
       AND password = '$password'



--- de normale login-poging

URL IN de browser:
/code/inlog.php?username=Skip&password=veilig

De query IS dan:
    SELECT COUNT(*)
      FROM somewhere
     WHERE username = 'Skip'
       AND password = 'veilig'


--- de hack-poging...

URL IN de browser:
/code/inlog.php?username=Skip&password=' OR ''='

De query IS dan:
    SELECT COUNT(*)
      FROM somewhere
     WHERE username = 'Skip'
       AND password = '' OR ''=''    (dit IS altijd TRUE...)