for my $key ( keys %new ) { my $all_strings = join " ", @{ $new{$key}->{strings} }; my $length = $new{$key}->{length}; print "$key\t$all_strings\t$length\n"; my $insert_sth = $dbh->prepare( 'INSERT INTO daten (New, Merge, Length) VALUES( ?, ?, ? )' ); $insert_sth->execute( $key, $all_strings, $length ); }