#!/usr/bin/perl

########################################################
#                                                      #
# objek adalah untuk pengkalan data seperti berikut    #
#                                                      #
#  table : pelajar                                     #
# +--------------+--------------+                      #
# | pelajar_id   | int          |                      #
# +--------------+--------------+                      #
# | tarikh_lahir | datetime     |                      #
# +--------------+--------------+                      #
# | jantina      | varchar(10)  |                      #
# +--------------+--------------+                      #
# | nama         | varchar(100) |                      #
# +--------------+--------------+                      #
#                                                      #
# objek pelajar                                        #
# =============                                        #
# variable                                             #
# --------                                             #
# pelajar_id                                           #
# tarikh_lahir                                         #
# jantina                                              #
# nama                                                 #
#                                                      #
# method                                               #
# --------                                             #
# new()                                                #
# next_id()                                            #
# get_pelajar()                                        #
# save()                                               #
# get_all()                                            #
# set_var()                                            #
#                                                      #
# contoh penggunaan                                    #
# =================                                    #
#                                                      #
# use pelajar;                                         #
#                                                      #
# $pelajar = pelajar->new();                           #
#                                                      #
# $pelajar->set_var(                                   #
#    nama         => "Khairil Iszuddin Ismail",        #
#    jantina      => "lelaki",                         #
#    tarikh_lahir => "1979-05-30");                    #
#                                                      #
# $pelajar->save();                                    #
#                                                      #
# print $pelajar->pelajar_id;                          #
#                                                      #
########################################################

use DBI;

package Pelajar;

$dbh = DBI->connect('dbi:mysql:database_name', 'username', 'password');

#----------------------------#
# membina satu objek pelajar #
#----------------------------#
sub new
{
	my $class = shift;
	my (%params) = @_;
	my $self = {};
	bless $self, $class;

	$self->set_var(
		pelajar_id => '',
		nama => '',
		jantina => '',
		tarikh_lahir => ''
	);

	if(defined $params{pelajar_id})
	{
		$self->set_var(pelajar_id => $params{pelajar_id});
		$self->get_pelajar();
	}
	return $self;
}

#----------------------------------------------------#
# mendapatkan pelajar_id berikutnya untuk rekod baru #
#----------------------------------------------------#
sub next_id
{
	my $self = shift;
	$sql = "SELECT pelajar_id FROM pelajar ORDER BY pelajar_id LIMIT 1";
	$sth = $dbh->prepare($sql);
	$sth->execute();
	my ($id) = $sth->fetchrow_array();
	$id++;
	$sth->finish();
	return $id;	
}

#------------------------------------------#
# simpan data pelajar dalam pengkalan data #
#------------------------------------------#
sub save
{
	my $self = shift;
	my (%params) = @_;
	
	$b = $self->nama;
	$c = $self->jantina;
	$d = $self->tarikh_lahir;
	
	if($self->pelajar_id eq '')
	{
		$self->set_var(pelajar_id => $self->next_id());
		$a = $self->pelajar_id;
		$sql  = "INSERT INTO pelajar (pelajar_id, nama, jantina, tarikh_lahir) ";
		$sql .= "VALUES ($a, '$b', '$c', '$d') ";
	}
	else
	{
		$a = $self->pelajar_id;
		$sql  = "UPDATE pelajar SET nama='$b', jantina='$c', tarikh_lahir='$d' ";
		$sql .= "WHERE pelajar_id = $a";
	}
	$sth = $dbh->prepare($sql);
	$result = $sth->execute();
	return($result);
}

#------------------------------------#
# memulangkan semua data dalam rekod #
#------------------------------------#
sub get_all
{
	my $self = shift;
	my @pelajar2 = ();
	
	$sql  = "SELECT pelajar_id, nama, tarikh_lahir, jantina ";
	$sql .= "FROM pelajar";
	$sth = $dbh->prepare($sql);
	$sth->execute();

	if($sth->rows() > 0)
	{
		while(($pelajar_id,$nama,$tarikh_lahir,$jantina) = $sth->fetchrow_array())
		{
			$temp = $self->new();
			$temp->set_var(
				pelajar_id => $pelajar_id,
				nama => $nama,
				tarikh_lahir => $tarikh_lahir,
				jantina => $jantina
			);
			push(@pelajar2, $temp);
		}
	}
	return(@pelajar2);
}

#--------------------------------#
# memulangkan satu rekod pelajar #
#--------------------------------#
sub get_pelajar
{
	my $self = shift;
	my $sql, $sth;
	if($self->pelajar_id ne '')
	{
		$id = $self->pelajar_id;
		$sql  = "SELECT pelajar_id, nama, tarikh_lahir, jantina ";
		$sql .= "FROM pelajar ";
		$sql .= "WHERE pelajar_id = $id LIMIT 1";

		$sth = $dbh->prepare($sql);
		$sth->execute();
		if($sth->rows() > 0)
		{
			($pelajar_id,$nama,$tarikh_lahir,$jantina) = $sth->fetchrow_array();
			$self->set_var(
				pelajar_id => $pelajar_id,
				nama => $nama,
				tarikh_lahir => $tarikh_lahir,
				jantina => $jantina
			);
			$result = TRUE;
		}
		else
		{
			$self->set_var(pelajar_id => '');
			$result = FALSE;
		}
	}
	else
	{ $result = FALSE; }
	return($result);
}

#------------------------------#
# memulangkan nilai pelajar_id #
#------------------------------#
sub pelajar_id
{ my $self = shift; return $self->{pelajar_id}; }

#------------------------#
# memulangkan nilai nama #
#------------------------#
sub nama
{ my $self = shift; return $self->{nama}; }

#--------------------------------#
# memulangkan nilai tarikh_lahir #
#--------------------------------#
sub tarikh_lahir
{ my $self = shift; return $self->{tarikh_lahir}; }

#---------------------------#
# memulangkan nilai jantina #
#---------------------------#
sub jantina
{ my $self = shift; return $self->{jantina}; }

#----------------------------------------#
# membuat umpukan nilai kepada variables #
#----------------------------------------#
sub set_var
{
	my $self = shift;
	my (%params) = @_;
	
	if(defined($params{nama}))
	{ $self->{nama} = $params{nama}; }
	
	if(defined($params{pelajar_id}))
	{ $self->{pelajar_id} = $params{pelajar_id}; }
	
	if(defined($params{jantina}))
	{ $self->{jantina} = $params{jantina}; }
	
	if(defined($params{tarikh_lahir}))
	{ $self->{tarikh_lahir} = $params{tarikh_lahir}; }
}