设计DTO类

@Data
public class DishPageQueryDTO implements Serializable {private int page;private int pageSize;private String name;private Integer categoryId; //分类idprivate Integer status; //状态 0表示禁用 1表示启用}

设计VO类

@Data
@Builder
@NoArgsConstructor
@AllArgsConstructor
public class DishVO implements Serializable {private Long id;//菜品名称private String name;//菜品分类idprivate Long categoryId;//菜品价格private BigDecimal price;//图片private String image;//描述信息private String description;//0 停售 1 起售private Integer status;//更新时间private LocalDateTime updateTime;//分类名称private String categoryName;//菜品关联的口味private List<DishFlavor> flavors = new ArrayList<>();
}

Controller层

@GetMapping("/page")@ApiOperation("菜品分页查询")public Result<PageResult> page(DishPageQueryDTO dishPageQueryDTO) {log.info("菜品分页查询:{}", dishPageQueryDTO);PageResult pageResult = dishService.pageQuery(dishPageQueryDTO);//后绪步骤定义return Result.success(pageResult);}

Service层

 public PageResult pageQuery(DishPageQueryDTO dishPageQueryDTO) {PageHelper.startPage(dishPageQueryDTO.getPage(), dishPageQueryDTO.getPageSize());Page<DishVO> page = dishMapper.pageQuery(dishPageQueryDTO);//后绪步骤实现return new PageResult(page.getTotal(), page.getResult());}

Mapper层

Page<DishVO> pageQuery(DishPageQueryDTO dishPageQueryDTO);

在 DishMapper.xml 中编写SQL：

<select id="pageQuery" resultType="com.sky.vo.DishVO">select d.* , c.name as categoryName from dish d left outer join category c on d.category_id = c.id<where><if test="name != null">and d.name like concat('%',#{name},'%')</if><if test="categoryId != null">and d.category_id = #{categoryId}</if><if test="status != null">and d.status = #{status}</if></where>order by d.create_time desc
</select>