my $sql = join(",", @allsearchterms);
my $sth = $dbh->prepare("select * from table where value in($sql)");
# You need to place qutes arount the sql-items, but you'll get the point here...
$sth->execute();


##</code><code>##


my $qm = join ',', ('?') x @allsearchterms;
my $sth = $dbh->prepare("select * from table where value in($qm)");
$sth->execute(@allsearchterms);