Introduction

Start with a brief introduction about Spring Data JPA and its importance in simplifying database access. Mention how it eliminates boilerplate code and improves productivity.

Query Creation from Method Names

Explain how Spring Data JPA supports creating queries automatically from method names. Provide examples like findByLastname(String lastname), findByFirstnameAndLastname(String firstname, String lastname), etc.

public interface UserRepository extends JpaRepository<User, Long> {
    List<User> findByLastname(String lastname);
    List<User> findByFirstnameAndLastname(String firstname, String lastname);
    // other methods...
}

Using the @Query Annotation

Discuss the use of the @Query annotation to define custom JPQL or native SQL queries. Provide examples:

public interface UserRepository extends JpaRepository<User, Long> {
    @Query("SELECT u FROM User u WHERE u.lastname = ?1")
    List<User> findByLastname(String lastname);

    @Query(value = "SELECT * FROM Users u WHERE u.status = 1", nativeQuery = true)
    List<User> findAllActiveUsersNative();
}

Using @Query with Named Parameters

Explain how to use named parameters in @Query annotations:

public interface UserRepository extends JpaRepository<User, Long> {
    @Query("from User where name=:name")
    User findByName(@Param("name") String name);
}

Custom Repository Implementations

If the derived queries and @Query annotation do not meet your needs, discuss how to provide custom implementations for repository methods.

Conclusion

Wrap up the post by summarizing the key points. Encourage readers to try out these features in their own projects.