and/or consider using join to form a sql statement (still with placeholders) such as:

my $tmp = join "," map "?", @arr;
my $stmt = <<"EOT";
delete from table_name where field in ($tmp)
EOT

my $sth = $dbh->prepare($stmt);
$sth->execute(@arr);
[download]

Update:It's a delete statement. duh.