Spring Hibernate JPA 利用原生sql联表查询

Spring Hibernate JPA 利用原生sql联表查询

测试类 代码片.

	@Test
    public void getDeviceStatusList() throws Exception {
        String tenantId = "1e88104b7aeab10b6debf3a73521807";
        List<Object[]> list = deviceDao.getDeviceStatusList(tenantId);
        // 对象类型转换
        List<DeviceCustomerAttributeKvEntity> testViews = EntityUtil.castEntity(list, DeviceCustomerAttributeKvEntity.class);
        for(DeviceCustomerAttributeKvEntity dca: testViews) {
            System.out.println(dca.toString());
        }
    }

查询语句代码片

	// 查询设备状态列表 Created by Wenhui Huang 2019/03/11
    @Query(nativeQuery = true, value = "select d.name as deviceName, d.device_address as deviceAddress, d.device_longitude as deviceLongitude, " +
            "d.device_latitude as deviceLatitude, d.created_ts as deviceCreatedTs, d.updated_ts as deviceUpdatedTs, c.title as CustomerTitle, a.bool_v as CustomerBoolV from device d " +
                                       "left join customer c on d.customer_id = c.id " +
                                       "left join attribute_kv a on a.entity_id = d.id and a.entity_type = 'DEVICE' " +
                                       "where " +
                                       "d.tenant_id = :tenantId " +
                                       "order by d.id")
    List<Object[]> getDeviceStatusList(@Param("tenantId") String tenantId);

实体转换工具类 代码片

/**
 * @author Created by Wenhui
 * @description 实体转换工具类
 * @date 2019/3/11
 */
public class EntityUtil {
    //转换实体类
    public static <T> List<T> castEntity(List<Object[]> list, Class<T> clazz) throws Exception {
        List<T> returnList = new ArrayList<T>();
        Field[] fields = clazz.getDeclaredFields();
        Object[] co = new Object[fields.length];
        Class[] c2 = new Class[co.length];
        
        //确定构造方法
        for (int i = 0; i < co.length; i++) {
            co[i] = fields[i].getType();
            // 获取对应属性类型对应class
            Class<?> classs=Class.forName(co[i].toString().substring(6, co[i].toString().length()));
            c2[i] = classs;
        }

        for (Object[] o : list) {
            Constructor<T> constructor = clazz.getConstructor(c2);
            returnList.add(constructor.newInstance(o));
        }
        
        return returnList;
    }

}