It's always a best practice to put mapping in PK class who owns and has FK mapping of owned entity.
@OneToOneprivateMembers members;
@OneToMany(One Member can own multiple Products)
This mapping loads lazily by default hence leading to optimizing the performance. How?
Say we have 50 members, with 100000 products. Each time, we need 1 member, entire product will be loaded for this operation. So, better load products only when required. Thats's lazy loading.
Optional relationship type
@ManyToOne(Not used here but eg. Many Products owned by One Member)
Eager by default. So, don't go for this unless required.
@ManyToOne(fetch = FetchType.LAZY) - This again makes it lazy. But with same example as above, would you want to load entire 100000 products and work in the reverse way? No? Right, choice is yours.
This relationship type is also optional by default but can be made mandatory - @ManyToOne(optional = false)
If relationship type is mandatory, we can't save Member without a Product.
@ManyToMany(One member can read multiple books. And one book can be read by multiple members)
Configurations for optionality, fetch type, cascading effect can be done as in others
Common Tips
referencedColumnName isn't required for PK mapping. For non-PK mapping, it is required
