my ($sql, @placeholders);
if (@rows == 0)
{
  $sql = qq{SELECT 1};
  @placeholders = ($svr1, $ap1, $in);
}
else
{
  $sql = qq{SELECT 2};
  @placeholders = ($svr1, $ap);
}

my $sth = $dbh->prepare($sql);
$sth->execute(@placeholders);