A quick java spring boot app to explore JPA & many to many relationship with Lazy loading

An interesting unit test is CourseLazyLoadingTest.java which explores lazy loading.

1. It outputs the SQL generated by JPA to the log (stdout).
2. Shows off the use of @Transactional to avoid LazyInitializationException.
3. It shows how to use @Query to avoid N+1 queries.
4. Shows using Hibernate.isInitialized(obj) to see if obj has been fetched from the database.

In memory h2 database

run mvn spring-boot:run to start the application then visit http://localhost:8080/h2-console to view the database

Simple GUI

Visit http://localhost:8080/ to view the app

Swagger included