#!/usr/bin/perl -w

use strict;
use myObject;

my $T = myObject->new();

# We add a server by passing in the server name, and a hash ref of the
# credentials we want to add
$T->addServer('barrabas', { password=>"sa", hostname=>"devo.marcorp.or
+g" });
$T->printMe;

$T->deleteServer('default');
$T->printMe;

$T->removeServerMap;
$T->printMe;
[download]

package myObject;

$VERSION = 1.00;
use strict;
use warnings;
use diagnostics;
use vars qw(@ISA);

use Carp ();
$Carp::Verbose =1;
{
        my %serverMap = (
                default => {
                        ipaddress       => "127.0.0.1",
                        dsn             => "default",
                        userid          => "sa",
                        password        => "password",
                        instance        => "instance"
                        }
        );

        sub new {
                my ($slf, %args) = @_;
                my %array=();
                %array = (%args); #?
                my $self={};
                return bless $self;
        }

        sub printMe() {
                my ($self) = @_;
                print "------ Available Servers ------\n";
                for my $server (keys %serverMap) {
                        print "\nServer: ", $server, "\n";
                        my $hr = $serverMap{$server};
                        for my $cr (keys %{$serverMap{$server}}) {
                                print "\t$cr => $serverMap{$server}{$c
+r}\n";
                        }
                }
        }

        sub addServer() {
                my ($self, $srvName, $hrCreds) = @_;
                $serverMap{$srvName} = $hrCreds;
        }

        sub removeServerMap($) {
                my ($self) = @_;
                %serverMap = ();
        }

        sub deleteServer($){
                my ($self, $srvName) = @_;
                delete $serverMap{$srvName};
        }

}

1
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That's close, but you can only ever have one "object" at a time, as you're using package-level data. That means you have to access the data in the object, not in the server map. You also don't need the prototypes on methods, as they're useless here.

package myObject;

use strict;
use warnings;

use vars '$VERSION';
$VERSION = 1.00;

my %serverMap = (
    default => {
        ipaddress => "127.0.0.1",
        dsn       => "default",
        userid    => "sa",
        password  => "password",
        instance  => "instance"
    }
);

# use the arguments in $serverMap{ default } as attribute defaults
sub new
{
    my $class = shift;
    my %self  = ( %{ $serverMap{ default } }, @_ );
    bless \%self, $class;
}

sub printMe
{
    my $self = shift;
    print "------ Available Servers ------\n";
    for my $server ( keys %$self )
    {
        print "\nServer: ", $server, "\n";

        for my $cr ( keys %{ $self->{$server} } )
        {
            print "\t$cr => $self->{$server}{$cr}\n";
        }
    }
}

sub addServer
{
    my ( $self, $srvName, $hrCreds ) = @_;
    $self->{$srvName} = $hrCreds;
}

sub removeServerMap
{
    my $self = shift;
    %$self = ();
}

sub deleteServer
{
    my ( $self, $srvName ) = @_;
    delete $self->{$srvName};
}

1;
[download]

Update: Fixed a typo in the code.

i guess I am hugely confuse about when to use $self->...
in the first reply to my question, the code uses the
%serverMap directly in each of the methods.. i guess because i define it outside all methods, it is visible???...
but in yours, you use $self to access to it.
another question of mine: i se eyou make a new constructor (more compact one), but
don't quite get what it does? your decision for the change? my original verison has this package @ISA CLASS::Singleton...
to prevent users of this class to have more than 1 copy of serverMap
.. but from your comment in your psot, is that step necessary anymore? thanks

thanks for your reply. i wans thinking of using this as the
datastructure to collect the mssql server credentials then
issues sql statements to test against various data already
in the database. we will enver use live database as it is a
app that depends on a fresh installed embedded msdn or a
new or existing sql server. we have a set of sample
inputs, and want to do some query against the databse to
make sure the data has been inserted into the database.
but since there may be schema, change I was thinking about
using object
relational mapping to map my test code against the SQL..
but is there a similar test framewrok arleady exits? since this is a common problem, I
have a feeling I may be duplicating someone else work. I
cannot use MOCK database as the dev team only support MSSQL and MSDN. any suggestion?

This code is a real mess -- I don't even think it will compile due to syntax errors and until you understand those, figuring out the object part will be a real challenge.

I suggest you spend some time going back to some basic tutorials on OO Perl. Perhaps Tutorial: Introduction to Object-Oriented Programming or Perl Object Oriented Meta-Tutorial would be a good starting point to give you some examples to work from.

Best of luck