Dear All,
Be happy,
here are some question regarding Hibernate.
kindly give the answer with reasoning / litter bit explanation Thnaks in advance

Q-1 :

if we create one-to-many relation in mapping,is its mandatory also tell the many end about one, mean also define in mapping many-to-one

Q-2 :

i m using a legacy system (as/400), get data from as40 and fill some object
now i wanna delete existing record (having ID)
if we delete multiple records using session.delete(class,objID)

its only delete one record
then i insert new records from the object which i fill from as400
it send Error like
.hibernate.exception.ConstraintViolationException: could not update:

but i provide all information regard FK

kind some one send sample code and reading material which support me

A-1:
No it isn't mandatory.
But as far as I understand the information about the association is usually stored on "many" side.
So if you do not specify the relationship on the side which is responsible for "knowing" the association you may have problems with persisting those associations.
A-2:
Please provide more data: your model mapping and log.