use DBI;
my $pathname = qq|webdb.db.db3|;
my $cnstr = qq|DBI:SQLite:dbname=$pathname|;

my $filename = q|afile.txt|;

open(H, qq|afile.txt|) or die $!;
my @lines = <H>;
close(H);

my $IN = '(';
$IN .= join  ',', map { qq|\'$_\'|} grep {chomp} @lines;
$IN = 'select webpage from webpages_data WHERE id in ' . $IN . ')';
print $IN;
#produces : select webpage from webpages_data WHERE id in ('koko.htm','koko1.htm','koko2.htm','koko3.htm')

##</code><code>##

select webpage from webpages_data, mySelectedStuff WHERE webpage.id = mySelectedStuff.id AND ...

##</code><code>##

select webpage from webpages_data where webpage in (select id from mySelectedStuff WHERE ...)