/ 
DBIx-Class-0.08125
River stage three • 347 direct dependents • 457 total dependents
/ DBIx::Class::ResultSetColumn

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 ]

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 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 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.

AUTHORS

Luke Saunders <luke.saunders@gmail.com>

Jess Robinson

LICENSE

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