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 DBIx::Class::ResultSet.

   as_query
       Arguments: none
       Return Value: \[ $sql, @bind_values ]

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

       This is generally used as the RHS for a subquery.

   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 DBIx::Class::ResultSet 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 DBIx::Class::ResultSet but returns values rather than result 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 DBIx::Class::ResultSet.

   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 DBIx::Class::ResultSet but just returning the one value.

   single
       Arguments: none
       Return Value: $value

       Much like "single" in DBIx::Class::ResultSet fetches one and only one column value using
       the cursor directly. If additional rows are present a warning is issued before discarding
       the cursor.

   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 DBIx::Class::Schema for details.

AUTHOR AND CONTRIBUTORS

       See AUTHOR and CONTRIBUTORS in DBIx::Class

LICENSE

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