SpringData JPA的常用语法汇总

public interface JpaRepository<T, ID> extends PagingAndSortingRepository<T, ID>, QueryByExampleExecutor<T> {
    // 无条件，查询全部记录
    List<T> findAll();
    // 排序查询
    List<T> findAll(Sort var1);
    // 根据主键ID查询
    List<T> findAllById(Iterable<ID> var1);
    // 批量保存集合数据
    <S extends T> List<S> saveAll(Iterable<S> var1);

    void flush();
 
    <S extends T> S saveAndFlush(S var1);
    // 批量删除
    void deleteInBatch(Iterable<T> var1);
    // all in 全部删除
    void deleteAllInBatch();
    // 查询一条记录
    T getOne(ID var1);
    // 条件查询
    <S extends T> List<S> findAll(Example<S> var1);
    // 条件查询，带排序
    <S extends T> List<S> findAll(Example<S> var1, Sort var2);
}

// 构建user的Example对象
Example<User> example =Example.of(User);
List<User> users = userRepository.findAll(example);

@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.METHOD, ElementType.ANNOTATION_TYPE})
@QueryAnnotation
@Documented
public @interface Query {
    String value() default "";
    String countQuery() default "";
    String countProjection() default "";
    boolean nativeQuery() default false;
    String name() default "";
    String countName() default "";
}

@Query(value = "select task_id from task group by task_id", nativeQuery = true)
List<Task> queryByGroup();

@Query(value = "select task_id,task_date from task order by task_id", nativeQuery = true)
List<Task> queryOrder();

@Query(value = "select task_id,task_date from task where task_date >=? and task_date <=? and deleted=0 ", nativeQuery = true)
List<ApptTask> queryDate(@Param("startDate") String startDate, @Param("endDate") String endDate);

@Transactional(rollbackOn = Exception.class)
@Modifying
@Query(value = "update task set remark = ? where task_id=?", nativeQuery = true)
void updateRemark(@Param("remark") String remark, @Param("taskId") String taskId);

@Query(value =
      " select a.task_name, a.task_id,u.user_name" +
      " from task a " +
      " LEFT JOIN usert u" +
      " ON a.user_id = u.user_id" +
      " where  a.deleted=0  " +
      " AND if(:taskName!='',a.task_name =:taskName,1=1)" +
      " AND if(:startDate!='',a.task_date >=:startDate,1=1)" +
      " AND if(:endDate!='',a.task_date <=:endDate,1=1)" +
      " order by a.task_date desc"
      , 
      nativeQuery = true
      , 
      countQuery =
      " select count(*)" +
      " from task a " +
      " LEFT JOIN usert u" +
      " ON a.user_id = u.user_id" +
      " where  a.deleted=0  " +
      " AND if(:taskName!='',a.task_name =:taskName,1=1)" +
      " AND if(:startDate!='',a.task_date >=:startDate,1=1)" +
      " AND if(:endDate!='',a.task_date <=:endDate,1=1)" +
      " order by a.task_date desc")
Page<Map<String,Object>> queryUserTaskPage(@Param("taskName") String taskName, @Param("startDate") LocalDate startDate, @Param("endDate") LocalDate endDate, @Param("pageable") Pageable pageable);