通过注解我们都自动生成表，再新建repository，可以查询表数据；这里我们介绍mysql的视图查询，关联多个表

• 先新建视图（如果先新建视图，可能注解会帮你生成表，而不是我们想要的视图）
• 视图这里简单展示下，不做细讲,视图语句如下：

   select `event`.`id` AS `EVENTID`,`event`.`code_year` AS `CODE_YEAR`,`event`.`code_num` AS `CODE_NUM`,`event`.`event_resource` AS `EVENT_RESOURCE`,`event`.`event_location` AS `LOCATION`,`event`.`islock` AS `ISCLOCK`,`event`.`clock_man` AS `CLOCKMAN_ID`,`clockm`.`user_name` AS `CLOCKMAN`,`evt_flow`.`limit_time` AS `TACHE_LIMIT_TIME`,`evt_flow`.`recieve_role` AS `FLOW_RECEIVE_ROLE_ID`,`evt_flow`.`receive_dept` AS `FLOW_RECELVE_DEPT_ID` from ((`evt_t_event` `event` join `evt_t_accept_flow` `evt_flow` on((`event`.`id` = `evt_flow`.`event_id`))) join `pmi_t_user` `clockm` on((`event`.`clock_man` = `clockm`.`id`))) where (`event`.`db_status` > 0)
  

• 创建java实体类，对应视图

   @Entity
    @Table(name = "v_todo_event_list")
    public class ToDoEventList implements Serializable {
    
        @Id //这个是必须的，不然启动报错
    
       private long EVENTID;
       private String CODE_YEAR;
       private int  CODE_NUM;
       private int EVENT_RESOURCE;
       private String LOCATION;
       private int ISCLOCK;
       private long CLOCKMAN_ID;
       private String CLOCKMAN;
       private int TACHE_LIMIT_TIME;
       private long FLOW_RECEIVE_ROLE_ID;
       private long FLOW_RECELVE_DEPT_ID;
      
      。。。。。。set get
  
         @Override
    	    public String toString() {
    	        return "ToDoEventList{" +
    	                "EVENTID=" + EVENTID +
    	                ", CODE_YEAR='" + CODE_YEAR + '\'' +
    	                ", CODE_NUM=" + CODE_NUM +
    	                ", EVENT_RESOURCE=" + EVENT_RESOURCE +
    	                ", LOCATION='" + LOCATION + '\'' +
    	                ", ISCLOCK=" + ISCLOCK +
    	                ", CLOCKMAN_ID=" + CLOCKMAN_ID +
    	                ", CLOCKMAN='" + CLOCKMAN + '\'' +
    	                ", TACHE_LIMIT_TIME=" + TACHE_LIMIT_TIME +
    	                ", FLOW_RECEIVE_ROLE_ID=" + FLOW_RECEIVE_ROLE_ID +
    	                ", FLOW_RECELVE_DEPT_ID=" + FLOW_RECELVE_DEPT_ID +
    	                '}';
    	    }
     }
  

• 创建Repository类

    public interface IToDoEventRepository extends JpaRepository<ToDoEventList,Long> , JpaSpecificationExecutor<ToDoEventList> {
      ToDoEventList findById(long id);
    }
  

• 方法调用：

    @Autowired
    IToDoEventRepository toDoEventRepository;
  

    ToDoEventList eventList = toDoEventRepository.findById(1);
    LOGGER.info(eventList);
  

• 打印结果：