package SQL::OOP::Update;
use strict;
use warnings;
use SQL::OOP::Base;
use SQL::OOP::Where;
use SQL::OOP::Dataset;
use base qw(SQL::OOP::Command);
	
	sub ARG_TABLE()		{1} ## no critic
	sub ARG_DATASET()	{2} ## no critic
	sub ARG_FROM()		{3} ## no critic
	sub ARG_WHERE()		{4} ## no critic
	
	### ---
	### Get Names of set arguments in array ref
	### ---
	sub KEYS {
		
		return [ARG_TABLE, ARG_DATASET, ARG_FROM, ARG_WHERE];
	}
	
	### ---
	### Get prefixes for each clause in hash ref
	### ---
	sub PREFIXES {
		
		return {
			ARG_TABLE()	 	=> 'UPDATE',
			ARG_DATASET() 	=> 'SET',
			ARG_FROM() 		=> 'FROM',
			ARG_WHERE() 	=> 'WHERE',
		}
	}
	
	### ---
	### Constructor
	### ---
	sub new {
		
		my ($class, %hash) = @_;
		return $class->SUPER::new(%hash);
	}
	
	### ---
	### Set elements
	### ---
	sub set {
		
		my ($class, %hash) = @_;
		return $class->SUPER::set(%hash);
	}
	
	### ---
	### Get SQL snippet
	### ---
	sub to_string {
		
		my ($self) = @_;
		$self->{array}->[1]->generate(SQL::OOP::Dataset->MODE_UPDATE);
		return shift->SUPER::to_string(@_);
	}
	
	### ---
	### Get binded values in array
	### ---
	sub bind {
		
		return shift->SUPER::bind(@_);
	}

1;

__END__

=head1 NAME

SQL::OOP::Update

=head1 SYNOPSIS

    my $update = SQL::OOP::Update->new;

    # set clause by plain text
    $update->set(
        $update->ARG_TABLE      => 'some_table',
        $update->ARG_DATASET    => 'a = b, c = d',
        $update->ARG_WHERE      => 'a = c',
    );
    
    # reset clauses using objects
    $update->set(
        $select->ARG_TABLE      => SQL::OOP::ID->new('some_table'),
        $update->ARG_DATASET    => SQL::OOP::Dataset->new(%data),
        $select->ARG_WHERE      => $where->cmp('=', "some_fileld", 'value')
    );
    my $sql  = $update->to_string;
    my @bind = $update->bind;

=head1 DESCRIPTION

SQL::OOP::Select class represents Select commands.

=head1 SQL::OOP::Update CLASS

=head2 SQL::OOP::Update->new(%clause)

Constructor. It takes arguments in hash. The Hash keys are provided by
following methods. They can call either class method or instance method.
    
    ARG_TABLE
    ARG_DATASET
    ARG_FROM
    ARG_WHERE

=head2 $instance->set(%clause)

This method resets the clause data. It takes same argument as constructor.

=head2 $instance->to_string

=head2 $instance->bind

=head1 CONSTANTS

=head2 KEYS

=head2 PREFIXES

=head2 ARG_TABLE

argument key for TABLE(=1)

=head2 ARG_DATASET

argument key for DATASET(=2)

=head2 ARG_FROM

argument key for FROM clause(=3)

=head2 ARG_WHERE

argument key for WHERE clause(=4)

=head1 AUTHOR

Sugama Keita, E<lt>sugama@jamadam.comE<gt>

=head1 COPYRIGHT AND LICENSE

Copyright (C) 2011 by Sugama Keita.

This program is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.

=cut