Select Code to Download

$VAR1 = {   #Variable is a hashRef
          'table' => [  #One key is "table", 
                        # which gives an arrayref.
...
                       'userName'
                     ]
        };

$rowHash = {id=>168, name=>'Jack'}; # create row
$tableHash->{$rowHash->{id}} = $rowHash; # add row to table
delete $tableHash->{$rowHash->{id}};  # delete row from table
$tableHash->{168}{name} = 'Jill'; #update single value