I know this solution is quite hacky, but I don't really have another idea right now. Try to add the following accessor to your resultsource class

sub col_name {
    my $self = shift;

    if (@_) {
        my $data = shift;
        my $sth = $self->result_source->schema->storage->dbh->prepare(
+"update table set col_name = ? where primary_key = ?");
        $sth->bind_param(1, $data, {TYPE => DBI::SQL_BINARY});
        $sth->bind_param(2, $self->primary_key);
        $sth->execute;
    }

    my $sth = $self->result_source->schema->storage->dbh->prepare("sel
+ect col_name from table where primary_key = ?");
    $sth->execute( $self->primary_key );

    my $result = $sth->fetchrow_hashref;
    return $result->{col_name};
}
[download]

I know that this piece of code somehow undermines the principles of DBIx::Class because the resultsource already knows what the table name is and how the primary_key is called. You may be able to change the hard-coded SQL queries to something smarter or you will probably also be able to use SQL::Abstract, which DBIx::Class uses internal as well, to build that query, but I didn't bother with that.

Also note that the code is completely untested.

Cheers, Flo