NAME

  DBIx::Class::ResultSetColumn - helpful methods for messing
  with a single column of the resultset

SYNOPSIS

  $rs = $schema->resultset('CD')->search({ artist => 'Tool' });
  $rs_column = $rs->get_column('year');
  $max_year = $rs_column->max; #returns latest year

DESCRIPTION

A convenience class used to perform operations on a specific column of a resultset.

METHODS

new

  my $obj = DBIx::Class::ResultSetColumn->new($rs, $column);

Creates a new resultset column object from the resultset and column passed as params. Used internally by get_column in the DBIx::Class::ResultSet manpage.

as_query (EXPERIMENTAL)

Arguments: none

Return Value: \[ $sql, @bind ]

Returns the SQL query and bind vars associated with the invocant.

This is generally used as the RHS for a subquery.

NOTE: This feature is still experimental.

next

Arguments: none

Return Value: $value

Returns the next value of the column in the resultset (or undef if there is none).

Much like next in the DBIx::Class::ResultSet manpage but just returning the one value.

all

Arguments: none

Return Value: @values

Returns all values of the column in the resultset (or undef if there are none).

Much like all in the DBIx::Class::ResultSet manpage but returns values rather than row objects.

reset

Arguments: none

Return Value: $self

Resets the underlying resultset's cursor, so you can iterate through the elements of the column again.

Much like reset in the DBIx::Class::ResultSet manpage.

first

Arguments: none

Return Value: $value

Resets the underlying resultset and returns the next value of the column in the resultset (or undef if there is none).

Much like first in the DBIx::Class::ResultSet manpage but just returning the one value.

min

Arguments: none

Return Value: $lowest_value

  my $first_year = $year_col->min();

Wrapper for ->func. Returns the lowest value of the column in the resultset (or undef if there are none).

min_rs

Arguments: none

Return Value: $resultset

  my $rs = $year_col->min_rs();

Wrapper for ->func_rs for function MIN().

max

Arguments: none

Return Value: $highest_value

  my $last_year = $year_col->max();

Wrapper for ->func. Returns the highest value of the column in the resultset (or undef if there are none).

max_rs

Arguments: none

Return Value: $resultset

  my $rs = $year_col->max_rs();

Wrapper for ->func_rs for function MAX().

sum

Arguments: none

Return Value: $sum_of_values

  my $total = $prices_col->sum();

Wrapper for ->func. Returns the sum of all the values in the column of the resultset. Use on varchar-like columns at your own risk.

sum_rs

Arguments: none

Return Value: $resultset

  my $rs = $year_col->sum_rs();

Wrapper for ->func_rs for function SUM().

func

Arguments: $function

Return Value: $function_return_value

  $rs = $schema->resultset("CD")->search({});
  $length = $rs->get_column('title')->func('LENGTH');

Runs a query using the function on the column and returns the value. Produces the following SQL:

  SELECT LENGTH( title ) FROM cd me

func_rs

Arguments: $function

Return Value: $resultset

Creates the resultset that func() uses to run its query.

throw_exception

See throw_exception in the DBIx::Class::Schema manpage for details.

=cut

sub throw_exception {
  my $self=shift;
  if (ref $self && $self->{_parent_resultset}) {
    $self->{_parent_resultset}->throw_exception(@_)
  } else {
    croak(@_);
  }
}

# _resultset # # Arguments: none # # Return Value: $resultset # # $year_col->_resultset->next # # Returns the underlying resultset. Creates it from the parent resultset if # necessary. # sub _resultset { my $self = shift;

  return $self->{_resultset} ||= $self->{_parent_resultset}->search(undef,
    {
      select => [$self->{_select}],
      as => [$self->{_as}]
    }
  );
  }

1;

AUTHORS

Luke Saunders <luke.saunders@gmail.com>

Jess Robinson

LICENSE

You may distribute this code under the same terms as Perl itself.