spring Data JPA

springboot與jpa整合步驟

主要接口

CrudRepository interface

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

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

  Optional<T> findById(ID primaryKey); 

  Iterable<T> findAll();               

  long count();                        

  void delete(T entity);               

  boolean existsById(ID primaryKey);   

  // … more functionality omitted.
}

PagingAndSortingRepository

public interface PagingAndSortingRepository<T, ID extends Serializable>
  extends CrudRepository<T, ID> {

  Iterable<T> findAll(Sort sort);

  Page<T> findAll(Pageable pageable);
}

獲取第二頁 每頁20條數據

PagingAndSortingRepository<User, Long> repository = // … get access to a bean
Page<User> users = repository.findAll(new PageRequest(1, 20));

獲取查詢數量

interface UserRepository extends CrudRepository<User, Long> {

  long countByLastname(String lastname);
}

刪除用戶

interface UserRepository extends CrudRepository<User, Long> {

  long deleteByLastname(String lastname);

  List<User> removeByLastname(String lastname);
}

查詢用戶

interface PersonRepository extends Repository<User, Long> {
 List<Person> findByLastname(String lastname);

 List<Person> findByEmailAddressAndLastname(EmailAddress emailAddress, String lastname);

  // Enables the distinct flag for the query
  List<Person> findDistinctPeopleByLastnameOrFirstname(String lastname, String firstname);
  List<Person> findPeopleDistinctByLastnameOrFirstname(String lastname, String firstname);

  // Enabling ignoring case for an individual property
  List<Person> findByLastnameIgnoreCase(String lastname);
  // Enabling ignoring case for all suitable properties
  List<Person> findByLastnameAndFirstnameAllIgnoreCase(String lastname, String firstname);

  // Enabling static ORDER BY for a query
  List<Person> findByLastnameOrderByFirstnameAsc(String lastname);
  List<Person> findByLastnameOrderByFirstnameDesc(String lastname);
}

屬性查詢

List<Person> findByAddressZipCode(ZipCode zipCode);
List<Person> findByAddress_ZipCode(ZipCode zipCode);//x.address.zipCode

分頁查詢帶條件

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

Slice<User> findByLastname(String lastname, Pageable pageable);

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

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

限制查詢結果數量

User findFirstByOrderByLastnameAsc();

User findTopByOrderByAgeDesc();

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

Slice<User> findTop3ByLastname(String lastname, Pageable pageable);

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

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

異步查詢

@Async
Future<User> findByFirstname(String firstname);               

@Async
CompletableFuture<User> findOneByFirstname(String firstname); 

@Async
ListenableFuture<User> findOneByLastname(String lastname);    

QueryDslPredicateExecutor

public interface QueryDslPredicateExecutor<T> {

  Optional<T> findById(Predicate predicate);  

  Iterable<T> findAll(Predicate predicate);   

  long count(Predicate predicate);            

  boolean exists(Predicate predicate);        

  // … more functionality omitted.
}

Querydsl Extension

http://www.querydsl.com/static/querydsl/latest/reference/html/ch02.html#jpa_integration

spring data jpa 利用@Query進行查詢

參考 http://blog.csdn.net/yingxiake/article/details/51016234

查詢關鍵字規範

https://docs.spring.io/spring-data/jpa/docs/2.0.2.RELEASE/reference/html/#_supported_query_keywords