How to read from database using Perl

Below is the perl script to write into Database.

Assumption: one database 'databasename' exists on host m/c, which has a table with name 'tablename' which further has at least one column with name 'date'.

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#!/usr/bin/perl
print "Content-type: text/html\n\n";

use DBI;
use CGI;

# CONFIG VARIABLES
$host = "fdb2.eu.pn";
$database = "databasename";
$dsn = "DBI:mysql:database=$database;host=$host";
$user = "someuser";
$pw = "somepassword";

# DB CONNECT
$dbh = DBI->connect($dsn, $user, $pw) or print "connect failed";
if ($dbh)
{
my $sth = $dbh->prepare("select * from tablename");
$sth->execute();
my $nf=$sth->{NUM_OF_FIELDS};
print "Num of fields = ". $nf;

if ($nf != 0){
my $id;
while($id=$sth->fetchrow_hashref()){
print "$id->{date}\n";
}
}
}