how emanate unfamiliar pivotal family entity framework?

i wish emanate new quarrel database list integrate unfamiliar pivotal family i haven't means hoop method calls need made. i have far:

db.models.order method = db.models.order.createorder( apple );
order.customerreference.attach( ( c db.customer where c.id == custid name c ).first() );
db.savechanges();

the formula unwell second line there, saying:

attach current operation when
source vigilant compared this
associated finish an added, deleted,
removed state. objects loaded
controlling notracking combine choice are
always detached.

any ideas?