Spring Boot Data Persistence with JPA 3

Question 1

Which interface should a Spring Data JPA repository extend to get CRUD operations plus pagination support?

Accepted Answer

JpaRepository

Answer

JpaRepository extends PagingAndSortingRepository and CrudRepository, providing the full set including pagination, sorting, and batch operations.

Question 2

What does the `@Transient` annotation do on an entity field?

Accepted Answer

Excludes the field from database persistence

Answer

@Transient tells JPA to skip the field during persistence, so it is never mapped to a database column.

Question 3

In Spring Boot, which property sets the Hibernate DDL generation strategy to create tables if they don't exist?

Accepted Answer

spring.jpa.hibernate.ddl-auto=update

Answer

The `update` strategy creates missing tables and columns but does not drop existing ones, making it safe for existing data.

Question 4

What does the `@ManyToMany` annotation require to store the relationship in the database?

Accepted Answer

A join table mapping the two entity PKs

Answer

@ManyToMany relationships are stored in a join (junction) table that holds the primary keys of both associated entities.

Question 5

Which method on `JpaRepository` fetches an entity and throws `EmptyResultDataAccessException` if not found?

Accepted Answer

findById()

Answer

findById() returns an Optional and does not throw, but the Spring Data `getById` / `getReferenceById` returns a proxy; for eager throwing behavior you typically use findById() + orElseThrow().

Spring Boot Practice Test

Spring Boot Practice Test

Spring Boot Data Persistence with JPA 3