noget nede under kategori

Du har to tabeller, f.eks.

CREATE TABLE kategorier (
  katid int auto_increment primary key not null
  ,katname varchar(50)
)

CREATE TABLE ting (
  tingid int auto_increment primary key not null
  ,katid int not null default 0
  ,tingname varchar(50)
)

en SQL der ser sådan ud:

$sql = "SELECT k.katname, t.tingname FROM kategorier k INNER JOIN ting t ON k.katid = t.katid ORDER BY t.katid, t.tingname";
$qh = mysql_query( $sql ) or die(mysql_error());
$old = "";
while ( $row = mysql_fetch_assoc( $qh ) )
{
  if ( $old != $row['katname'] )
  {
      echo "$row[katname]<br>---------<br>";
      $old = $row['katname'];
  }
  echo "$row[tingname]<br>";
}