foreach my $table( @some_list_of_tables ) {

  ## some code to read another .ini file into $config where
  ## the sections are cols and the k=v pairs are user=new_val
  ## 
  ## (for example!)

  foreach my $col (sort keys %$config) {
    my $sql = qq{ update $table set $col = ? where user = ?};
    my $sth = $dbh->prepare( $sql );
    
    while (my ($user, $new_val) = each %{$config->{$col}}) {
      $sth->execute( $new_val, $user );
    }
  }
}