Goal
Get knowledge about relationships and querying in JPA.
Advanced Mapping
1. Add gender attribute into Person entity.
2. Try to run main method and look to generated database schema.
3. Change gender attribute configuration to be mandatory (i.e. not null) and to be stored
as VARCHAR(6).
4. Modify main method to set appropriate gender to entities and try to execute main
method.
5. Add birthdate attribute with java.util.Date type.
6. Modify main method to set appropriate birthdate to entities and try to execute main
method.
7. Modify dump method to show also gender and birthdate attribute and try to execute main
method.
Relationships
Extend person entity
1. Add father attribute with Person type into Person entity and create uni-directional
relationship between person and its father.
2. Add new transaction to the end of main method that creates Paul Brown Jr. entity with
the same address as Paul Brown and set Paul Brown as his father.
3. Create Trait entity with attributes person and trait.
4. Create bi-directional OneToMany relationship between Person and Trait. Configure this
relationship to persist, update or delete all traits automatically when person is persisted,
updated or deleted.
5. Add new transaction to the end of main method that creates some person entity with at
least two traits..
Querying
JPQL
1. Modify main method to add also these entities:
a. John Novacek, Prague, 25. 4. 1968
b. Petr Novacek, Prague, 25. 4. 1986, son of John Novacek
c. Jane Novacek, Prague, 25. 4. 1986, daughter of John Novacek
2. Create method that returns all people with at least one children in database using named
query.
3. Try to call this method at the end of main method and print result to stdout in suitable
form.
4. Create method that returns list of person names for all person entities in database with
given birthdate.
5. Try to call this method at the end of main method and print result to stdout in suitable
form.
6. Create PersonTO class that contains attributes id, name and childrenCount.
7. Create method that returns list of PersonTO instances for all person entities in database
with given name.
8. Try to call this method at the end of main method and print result to stdout in suitable
form.
9. Create method that returns count of person entities with no children.
10. Try to call this method at the end of main method and print result to stdout in suitable
form.
Criteria API
1. Modify dump(...) method to be implemented using Criteria API.