[Perl] Moose 範例 - 銀行篇

#!/usr/bin/env perl

package BankAccount;
use Moose;
use Data::Dumper;

has 'balance' => (
  is => 'rw',
  isa => 'Str',
  default => 0
);

sub deposit {
  my ($self, $amount) = @_;
  $self->balance( $self->balance + $amount);
}

sub showBalance {
  my $self = @_;
  print "The balance is : \n";
 
}

my $savingAccount = BankAccount->new( balance => 250 );
print Dumper($savingAccount);
$savingAccount->deposit(100);
print Dumper($savingAccount);               
$savingAccount->showBalance();
 

[Perl] Linux 上使用 Perl 查詢 Microsoft SQL Server

Perl 連接 MySQL 這種就不用多說了，Google 一下就很多教學 今天來談的是 Linux 裡面如何查詢微軟的 MS SQL Server

簡介如下

建置環境 : CentOS v6.2
程式語言 : Perl v5.10.1

一開始需先安裝 FreeTDS 程式，但是 yum 預設並沒有這個套件，所以要先前置作業下載 CentOS epel RPM ， 記得看你的 CentOS 版本是 5 還是 6 找到對應的目錄去下載

安裝步驟
1. sudo su -
2. rpm -Uvh epel-release-6-8.noarch.rpm
3. vim /etc/yum.repos.d/epel.repo，把 [epel] 裡面的註解取消
4. yum update
5. yum install freetds.x86_64
6. yum install freetds-devel.x86_64
7. vim /etc/freetds.conf，新增如下

[SQLSERVER]
     host = your_sqlserver_hostname
     port = 1433
     tds version = 7.0


安裝完成後可以先執行 tsql 測試
 tsql -S sqlserver.hostname.com -U sqlusername -D your_db_name

進去後再下
select * from sys.Tables;
GO
quit

也可以改成 "一行執行"
printf "SELECT * FROM httpstatus\ngo\n" | tsql -S sqlserver.hostname.com -U sqlusername -P sqlpassword -D your_db_name

前置作業完成後，再來要安裝 Perl 模組 DBD::Sybase，你沒看錯真的是 Sybase 模組(緣由請參考這裡)

 安裝步驟
1. export SYBASE=/usr (這行要有不然安裝時會出現找不到 sybase library 錯誤)
2. cpanm DBD::Sybase

都完成後終於要開始寫程式啦, 程式碼如下
#!/usr/bin/perl

#use lib ('./modules');
use DBI;
use DBD::Sybase;

my $database = "your_db_name";
my $username = 'sqlusername';
my $password = 'sqlpassword';

#SQLSERVER 字串對應至 /etc/freetds.conf 裡面的 [SQLSERVER] tag
$dsn = "DBI:Sybase:server=SQLSERVER;database=$database";

my $dbh = DBI->connect($dsn, $username, $password) or die "Database connection not made : $DBI::errstr";

my $sql = "SELECT TOP 5 * FROM httpstatus order by testtime desc";
my $sth = $dbh->prepare( $sql );
$sth->execute() or die "unable to execute query $sql, error $DBI::errstr\n";

$rows = $sth->rows;

while ( @first = $sth->fetchrow_array ) {
        foreach $field (@first) {
                print "$field ";
        }
        print "\n";
}

$sth->finish();
undef $sth;
$dbh->disconnect();

print "Query successfully\n";

資考資料 : http://dolio.lh.net/~apw/doc/HOWTO/HOWTO-Connect_Perl_to_SQL_Server.pdf