Hibernate RelationShip

Both uni direction and bi direction
a.one-to-one
b.one-to-many
c.many-to many

A.one-to-one Relationship can be achieved in 3 ways.

1.Join Table ( separte table to maintain reationship)
2.Foreign Key ( relationship mainted in same table with foreign key)
3.Primary Key Column ( table 1 primarykey is user to retrieve table 2 primary key, if table 2 entity is updated separatly it's not the correct solution.It's applicable only for one to one.

B.one-to-Many:-
1.Join Table
2.foreign Key

Hibernate  strongly advise you to use a join table for one-to-many kind of association 
You don't have to (must not) define any physical mapping in the mappedBy side.


C.Many-to-Many
1.Only Join Table



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