use strict;
use warnings;
use utf8;
...
binmode(STDIN, ':encoding(cp1251)');
binmode(STDOUT,':encoding(cp866)');
binmode(STDERR,':encoding(cp866)');
use Encode;
$ARGV[$_] = decode('cp1251',$ARGV[$_]) foreach (0..$#ARGV);
no Encode;
...
sub dblink()
{
	$ENV{'NLS_LANG'} = 'RUSSIAN_CIS.UTF8';
	my $dbh = DBI->connect($datalink, $dbuser, $dbpass, {RaiseError => 0, AutoCommit => 0} );
	$dbh->do("ALTER SESSION SET NLS_NUMERIC_CHARACTERS = '. '");
	$dbh->do("ALTER SESSION SET NLS_DATE_FORMAT = 'YYYY-MM-DD'");
	$dbh->do("ALTER SESSION SET NLS_TIMESTAMP_FORMAT = 'YYYY-MM-DD HH:MI:SS'");
	return $dbh;
}

sub sqlcmd($;$)
{
	my $sql = shift||'';
	my $params = shift;
	my $q = $dbh->prepare($sql);
	if ($params && ref($params) eq 'HASH')
	{
		$q->bind_param(":$_", $params->{$_}) foreach keys(%{$params});
	}
	my $ret = $q->execute();
	{
		my @rows = ();
		while ( my $row = $q->fetchrow_hashref )
		{
			my $enc = {};
			$enc->{$_} = $row->{$_} foreach keys (%{$row});
			push @rows, $enc;
		}
		return \@rows;
	}
}
...

__DATA__

{sql_sample}
select ...
, 'тест1' as test_column
, 'тест2' as "тест_столбец"
from ...
where field like :find||'%'

$VAR1 = {
          'TEST_COLUMN' => "\x{442}\x{435}\x{441}\x{442}1",
          '\x{00d1}\x{0082}\x{00d0}\x{00b5}\x{00d1}\x{0081}\x{00d1}\x{0082}_\x{00d1}\x{0081}\x{00d1}\x{0082}\x{00d0}\x{00be}\x{00d0}\x{00bb}\x{00d0}\x{00b1}\x{00d0}\x{00b5}\x{00d1}\x{0086}' => "\x{442}\x{435}\x{441}\x{442}2",
        };

use Data::Dumper;
$Data::Dumper::Useqq = 1;
{
  no warnings 'redefine';
  sub Data::Dumper::qquote
  {
    my $s = shift;
    return "'$s'";
  }
}