MP实现分页条件查询

1. ------>详情gitee笔记
2. 这就是mp的分页插件：     userMapper.selectPage(page, queryWrapper);

3. public class DishController {
       @Autowired
       private DishService dishService;
   ​
       @GetMapping("/page")
       public Result<PageResult> page(DishPageQueryDTO dto) {
           PageResult page = dishService.page(dto);
           return Result.success(page);
       }
      }

4. @Service
   public class DishServiceImpl implements DishService {
       @Autowired
       private DishMapper dishMapper;
   ​
       @Override
       public PageResult page(DishPageQueryDTO dto) {
           LambdaQueryWrapper<Dish> lambdaQueryWrapper = new LambdaQueryWrapper<>();
           lambdaQueryWrapper.like(!StringUtils.isBlank(dto.getName()),Dish::getName, dto.getName())
                   .eq(!Objects.isNull(dto.getCategoryId()),Dish::getCategoryId, dto.getCategoryId()); // 添加了类别ID的查询条件
           IPage<Dish> dishIPage = new Page<>(dto.getPage(), dto.getPageSize());
           dishIPage = dishMapper.selectPage(dishIPage, lambdaQueryWrapper); // 使用 lambdaQueryWrapper 而不是 null
   ​
           List<DishVO> dishVOS = BeanUtil.copyToList(dishIPage.getRecords(), DishVO.class);
   ​
           return PageResult.builder().records(dishVOS).total(dishIPage.getTotal()).build();
       }
     }

5.  

   public interface DishMapper extends BaseMapper<Dish> {
   }

6. 配置类

   @Configuration
   public class MybatisPlusConfig {
       @Bean
       public PaginationInterceptor mybatisPlusInterceptor() {
           PaginationInterceptor paginationInterceptor = new PaginationInterceptor();
           // 设置请求的页面大于最大页后操作， true调回到首页，false 继续请求  默认false
           // paginationInterceptor.setOverflow(false);
           // 设置最大单页限制数量，默认 500 条，-1 不受限制
           paginationInterceptor.setLimit(1000);
           // 开启 count 的 join 优化,只针对部分 left join
           paginationInterceptor.setCountSqlParser(new JsqlParserCountOptimize(true));
           return paginationInterceptor;
       }
   }

 

语句2

    public PageDTO<CouponPageVO> pageCoupon(CouponQuery query) {
        LambdaQueryWrapper<Coupon> wrapper = new LambdaQueryWrapper<>();
        Page<Coupon> couponPage = new Page<>();
        couponPage.setSize(query.getPageSize());
        couponPage.setPages(query.getPageNo());
        wrapper.like(StrUtil.isNotBlank(query.getName()),Coupon::getName, query.getName())
                .eq(query.getType()!=null,Coupon::getType,query.getType())
                .eq(query.getStatus()!=null,Coupon::getStatus,query.getStatus());

        this.page(couponPage,wrapper);
        List<Coupon> records = couponPage.getRecords();

        List<CouponPageVO> voList = BeanUtil.copyToList(records, CouponPageVO.class);
        return PageDTO.of(couponPage, voList);
    }
}

 

语句3：

注释的是mybatis，非注释的是MP

    public PageResult historyOrders(OrdersPageQueryDTO source) {
//        PageHelper.startPage(source.getPage(),source.getPageSize());
//        source.setUserId(BaseContext.getCurrentId());
//        Page<OrderVO> orderVOPage = orderRepository.pageHistoryOrders(source);
        Page<OrderVO> page = new Page<>(source.getPage(), source.getPageSize());
        orderRepository.pageHistoryOrders(page, source);
        return new PageResult(page.getTotal(), page.getRecords());
    }