WHERE database NOT LIKE '%tempdb%'
  AND (
       keyword LIKE '%create%'
    OR keyword LIKE '%delete%'
    OR keyword LIKE '%insert%'
    ...
  )

##</code><code>##

my @patterns = qw/create delete insert update drop/;
my $query = "@sqlstatement"; # don't know what you already have in @sqlstatement though
$query .= qq{WHERE database NOT LIKE '%tempdb%';
$query .= qq{AND (};
$query .= join " OR ",
            map { qq{keyword LIKE '%$_%'} }
              @patterns;
$query .= qq{)};

sth=$dbh->prepare( $query );
$sth->execute;
while ($data = $sth->fetchrow_arrayref()) {
   # the query did all of our checking, so we don't need to check anything.
   print "$data->[3] $data->[9] $data->[10] $data->[13]\n";
}