SpringDataJpa:JpaRepository增删改查操作

public interface UserRepository extends JpaRepository<User, Long> {

}

@Test

public void testBaseQuery() throws Exception {

     User user= new User();

     userRepository.findAll();

     userRepository.findOne(1l);

     userRepository.save(user);

     userRepository.delete(user);

     userRepository.count();

     userRepository.exists(1l);

     // ...

}

class People{

        private String firstName;

        private String lastName;

}

findByLastNameAndFirstName(String lastName,String firstName);

Page<UserModel> findByName(String name, Pageable pageable);

List<UserModel> findByName(String name, Sort sort);

@Test

public void testPageQuery() throws Exception {

     int page= 1 ,size= 10 ;

     Sort sort = new Sort(Direction.DESC, "id" );

     Pageable pageable = new PageRequest(page, size, sort);

     userRepository.findALL(pageable);

     userRepository.findByUserName( "testName" , pageable);

}

@NamedQuery (name = "UserModel.findByAge" ,query = "select o from UserModel o where o.age >= ?1" )

public List<UserModel> findByAge( int age);

@Query (value= "select * from tbl_user where name like %?1" ,nativeQuery= true )

public List<UserModel> findByUuidOrAge(String name);

@Query (value= "select o from UserModel o where o.name like %:nn" )

public List<UserModel> findByUuidOrAge( @Param ( "nn" ) String name);

User findFirstByOrderByLastnameAsc();

User findTopByOrderByAgeDesc();

Page<User> queryFirst10ByLastname(String lastname, Pageable pageable);

List<User> findFirst10ByLastname(String lastname, Sort sort);

List<User> findTop10ByLastname(String lastname, Pageable pageable);

public interface HotelSummary {

     City getCity();

     String getName();

     Double getAverageRating();

     default Integer getAverageRatingRounded() {

         return getAverageRating() == null ? null : ( int ) Math.round(getAverageRating());

     }

}

@Query ( "select h.city as city, h.name as name, avg(r.rating) as averageRating "

         + "from Hotel h left outer join h.reviews r where h.city = ?1 group by h" )

Page<HotelSummary> findByCity(City city, Pageable pageable);

@Query ( "select h.name as name, avg(r.rating) as averageRating "

         + "from Hotel h left outer join h.reviews r  group by h" )

Page<HotelSummary> findByCity(Pageable pageable);

Page<HotelSummary> hotels = this .hotelRepository.findByCity( new PageRequest( 0 , 10 , Direction.ASC, "name" ));

for (HotelSummary summay:hotels){

         System.out.println( "Name" +summay.getName());

     }

@Modifying

@Query (value= "update UserModel o set o.name=:newName where o.name like %:nn" )

public int findByUuidOrAge( @Param ( "nn" ) String name, @Param ( "newName" ) String newName);

@Query (value = "delete from r_upa where user_id= ?1 and point_indecs_id in (?2)" , nativeQuery = true )

@Modifying

void deleteByUserAndPointIndecs(Long uid, List<Long> hids);

@NoRepositoryBean

public interface JpaRepository<T, ID> extends PagingAndSortingRepository<T, ID>, QueryByExampleExecutor<T> {

     /**

   * Deletes the given entities in a batch which means it will create a single {@link Query}. Assume that we will clear

   * the {@link javax.persistence.EntityManager} after the call.

   *

   * @param entities

      * 批量解绑多个，优势：只会形成一个SQL语句

   */

  void deleteInBatch(Iterable<T> entities);

  /**

   * Deletes all entities in a batch call.

   */

  void deleteAllInBatch();

}

@NoRepositoryBean

public interface CrudRepository<T, ID> extends Repository<T, ID> {

     /**

   * Deletes the entity with the given id.

   *

   * @param id must not be {@literal null}.

   * @throws IllegalArgumentException in case the given {@code id} is {@literal null}

   */

  void deleteById(ID id);

  /**

   * Deletes a given entity.

   *

   * @param entity

   * @throws IllegalArgumentException in case the given entity is {@literal null}.

   */

  void delete(T entity);

  /**

   * Deletes the given entities.

   *

   * @param entities

   * @throws IllegalArgumentException in case the given {@link Iterable} is {@literal null}.

   */

  void deleteAll(Iterable<? extends T> entities);

  /**

   * Deletes all entities managed by the repository.

   */

  void deleteAll();

}

@NoRepositoryBean

public interface JpaRepository<T, ID> extends PagingAndSortingRepository<T, ID>, QueryByExampleExecutor<T> {

  /*

   * (non-Javadoc)

   * @see org.springframework.data.repository.CrudRepository#save(java.lang.Iterable)

   */

  <S extends T> List<S> saveAll(Iterable<S> entities);

  /**

   * Flushes all pending changes to the database.

   */

  void flush();

  /**

   * Saves an entity and flushes changes instantly.

   *

   * @param entity

   * @return the saved entity

   */

  <S extends T> S saveAndFlush(S entity);

}

@NoRepositoryBean

public interface CrudRepository<T, ID> extends Repository<T, ID> {

  /**

   * Saves a given entity. Use the returned instance for further operations as the save operation might have changed the

   * entity instance completely.

   *

   * @param entity must not be {@literal null}.

   * @return the saved entity will never be {@literal null}.

   */

  <S extends T> S save(S entity);

  /**

   * Saves all given entities.

   *

   * @param entities must not be {@literal null}.

   * @return the saved entities will never be {@literal null}.

   * @throws IllegalArgumentException in case the given entity is {@literal null}.

   */

  <S extends T> Iterable<S> saveAll(Iterable<S> entities);

}

@Transactional

   public <S extends T> List<S> save(Iterable<S> entities) {

       List<S> result = new ArrayList<S>();

       if (entities == null ) {

           return result;

       }

       for (S entity : entities) {

           result.add(save(entity));

       }

       return result;

   }

@Transactional

     public <S extends T> S save(S entity) {

         if (entityInformation.isNew(entity)) {

             em.persist(entity); //是新的就插入

             return entity;

         } else {

             return em.merge(entity); //不是新的merge

         }

     }