Java Persistence With Hibernate - reading notes (3)

30 min

1. the problem of granularity
2. the problem of subtypes
3. the problem of identity
4. the problem of associations

Table associations are always one-to-many or one-to-one. If you wish to represent a many-to-many association in a relational database, you must introduce a new table, called a link table.

5. the problem of data navigation
sql joins
join (inner join)
left join (left outer join)
right join (right outer join)
full join