first of all you have to provide more code snippets for better answer, ORMs work with entity, so you must fetch the corresponding entity and set on the turn object, or you can create a new object of for example Client and set the client_id on id and then set client on turn object, Hibernate works with primary key (default is id). note that annotate mandatory relations by @NotNull and also optional=false (for auto generating table by jpa) hope it helps