use DBI;
my $dbh = DBI->new(
    "dbi:mysql:host=$host;database=$database", $db_user, $db_password,
);

my $sth = $dbh->prepare( 'select * from users where csl = ?' );
$sth->execute( 'hasanche' );
while ( my $row = $sth->fetch ) {
    print "$row->{whatever_col1_is_called}\n";
}
$sth->finish;