public interface CommodityMapper {
    int deleteByPrimaryKey(Integer productId);

    int insert(Commodity record);

    Commodity selectByPrimaryKey(Integer productId);

    List<Commodity> selectAll();

    List<Commodity> getType(int id);

    int updateByPrimaryKey(Commodity record);

    int getCount();

    List<Commodity> SearchCommodity(@Param("productName") String productName);//注意传参的名字必须要和Mapper文件一致

}

 //搜索

    @RequestMapping(path = "/search", method = RequestMethod.GET)

    public ResponseEntity Search(String productName) {

        if (commodityService.SearchCommodity(productName).size() != 0) {

            return ResponseEntity.ok(commodityService.SearchCommodity(productName));

        } else {

            return ResponseEntity.ok("error");

        }

    }

    <select id="SearchCommodity"  resultType="string" resultMap="BaseResultMap">

select

c.product_id,

c.product_name,

c.product_content,

s.product_specs,

s.product_price,

d.product_simg

from commodity  c

cross join Standard  s

on c.product_id=s.product_id

cross join dommodityAttribute d

on  c.product_id=d.product_id

where c.product_name like concat('%',#{productName},'%')  group by c.product_id

    </select>