DBIx::Class::ResultSetColumn

(source, CPAN)

NAME
SYNOPSIS
DESCRIPTION
METHODS
- new
- as_query
- next
- all
- reset
- first
- single
- min
- min_rs
- max
- max_rs
- sum
- sum_rs
- func
- func_rs
- throw_exception
FURTHER QUESTIONS?
COPYRIGHT AND LICENSE

#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.

#FURTHER QUESTIONS?

Check the list of additional DBIC resources.

#COPYRIGHT AND LICENSE

This module is free software copyright by the DBIx::Class (DBIC) authors. You can redistribute it and/or modify it under the same terms as the DBIx::Class library.

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