经典电商购物车数据结构及实现过程「电商的购物车有哪些逻辑」

最近有购物车逻辑,涉及到购物车列表,这里说一下自己的实现方式,各位如果有更好的方式欢迎评论区留言.

1.与前端协定好的接口协议:

[{"goodsSpecInfoList": [{"goodsId": 3,"newPrice": 127.00,"oldPrice": 129.00,"specContent": "","specContentInfos": [{"keyName": "长度","specKeyId": 1,"specValueId": 2,"valueName": "8mm"},{"keyName": "宽度","specKeyId": 2,"specValueId": 4,"valueName": "4m"}],"specImg": "珊瑚/灰色图片"},{"goodsId": 4,"newPrice": 135.00,"oldPrice": 139.00,"specContent": "","specContentInfos": [{"keyName": "长度","specKeyId": 1,"specValueId": 2,"valueName": "8mm"},{"keyName": "宽度","specKeyId": 2,"specValueId": 4,"valueName": "4m"}],"specImg": "水蓝/灰色图片"}],"sellerHeadPic": "3.jpg","sellerId": 3,"sellerNickName": "小花"}]

整体的结构解读:

商家基本信息(昵称 头像 id)

商品列表信息(goodsSpecInfoList)

商品1基本信息

规格具体信息(specContentInfos)

商品2基本信息

规格具体信息(specContentInfos)

2.具体实现的逻辑:

根据用户名查询购物车订单中的商家信息.然后查询每一个商家信息下面关联的商品规格信息,此处使用mybatis的collection标签.由于规格表中存储的是规格id与规格项id,所以根据规格id信息去规格项与规格表中查询了对应的规格名称与规格项名称.

3.dao接口:

public interface GoodsCartMapper{ // 根据商品规格id查询对应的名称 List<SpecContentInfo> findSpecContentInfo(@Param("specContentList") List specContentList); // 查询购物车信息 List<GoodsCartReturnVo> findReturnGoodsCart(String login);}

4.dao映射配置文件(头文件以及命名空间已省略):

<!--根据规格项keyId以及valueId查询对应的名称--><select id="findSpecContentInfo" parameterType="java.util.List" resultType="com.it.tao.review_springboot_mybatis.domain.goodsCart.SpecContentInfo">SELECT goods_spec_key.id specKeyId,goods_spec_key.`key_name`,goods_spec_value.`id` specValueId,goods_spec_value.`value_name`FROM goods_spec_key,goods_spec_value WHERE (goods_spec_key.id,goods_spec_value.`id`) in<foreach collection="specContentList" open="(" separator="," close=")" item="specContent">(#{specContent.specKeyId},#{specContent.specValueId})</foreach></select><resultMap id="goodsCartReturnMap" type="com.it.tao.review_springboot_mybatis.domain.goodsCart.GoodsCartReturnVo"><id column="id" property="sellerId"></id><collection property="goodsSpecInfoList" column="id" javaType="java.util.List" ofType="com.it.tao.review_springboot_mybatis.domain.goodsCart.GoodsSpecInfo"select="findSpecContentStr"></collection></resultMap><!--查询商品购物车新--><select id="findReturnGoodsCart" parameterType="string" resultMap="goodsCartReturnMap">SELECT goods_seller.id,goods_seller.`nick_name` seller_nick_name,goods_seller.`head_pic` seller_head_pic,goods_cart.`id` goods_cart_id FROM goods_cart,goods_sellerWHERE login=#{login} AND goods_cart.`saler_id`=goods_seller.`id` GROUP BY saler_id ORDER BY saler_id</select><!--根据商家id查询规格id,然后根据规格id查询对应的规格内容--><select id="findSpecContentStr" parameterType="int" resultType="com.it.tao.review_springboot_mybatis.domain.goodsCart.GoodsSpecInfo">SELECT goods_id,spec_content,spec_img,old_price,new_price FROM goods_spec WHERE id IN (SELECT spec_id FROM goods_cart WHERE saler_id=#{sellerId})</select>

5.涉及到的实体类(省略get/set)

返回页面的购物车实体类:

public class GoodsCartReturnVo { private int sellerId; private String sellerNickName; private String sellerHeadPic; // 同一商家下关联的规格商品信息 private List<GoodsSpecInfo> goodsSpecInfoList;}

购物车中商品规格基本信息:

public class GoodsSpecInfo { private int goodsId; private String specImg; private BigDecimal oldPrice; private BigDecimal newPrice; // 对应数据库中商品规格json字符串 private String specContent; // 商品规格json字符串转化成的json对象集合,带有规格id以及规格名称 private List<SpecContentInfo> specContentInfos;}

规格参数实体类:

public class SpecContentInfo { private int specKeyId; private int specValueId; private String keyName; private String valueName;}

规格id组合实体类:

public class SpecContentVo { private int specKeyId; private int specValueId;}

说明:GoodsCartReturnVo中包含GoodsSpecInfo,GoodsSpecInfo中包含SpecContentInfo

6.涉及到的表(测试数据参考):

购物车表:

DROP TABLE IF EXISTS `goods_cart`;CREATE TABLE `goods_cart` (`id` INT(11) NOT NULL AUTO_INCREMENT,`saler_id` INT(11) NOT NULL COMMENT '商家id',`spec_id` INT(11) NOT NULL COMMENT '选择商品规格id',`login` VARCHAR(255) NOT NULL COMMENT '用户login字段',`num` INT(11) DEFAULT NULL COMMENT '购买数量',`create_time` DATETIME DEFAULT NULL COMMENT '创建时间',`update_time` DATETIME DEFAULT NULL COMMENT '修改时间',PRIMARY KEY (`id`)) ENGINE=INNODB AUTO_INCREMENT=11 DEFAULT CHARSET=utf8 COMMENT='商品购物车表';/*Data for the table `goods_cart` */INSERT INTO `goods_cart`(`id`,`saler_id`,`spec_id`,`login`,`num`,`create_time`,`update_time`) VALUES (1,2,1,'155984905041578',8,'2020-09-10 10:58:31','2020-09-10 13:57:44'),(2,2,2,'155984905041578',1,'2020-09-10 11:18:06',NULL),(8,3,4,'155984905041578',1,'2020-09-10 15:15:31',NULL),(9,3,3,'155984905041578',2,'2020-09-10 15:15:58',NULL),(10,4,2,'1132456',1,'2020-09-10 15:21:39',NULL);

商品规格表(spec_content存储规格id与规格项组成的json格式):

DROP TABLE IF EXISTS `goods_spec`;CREATE TABLE `goods_spec` (`id` INT(11) NOT NULL AUTO_INCREMENT,`goods_id` INT(11) NOT NULL COMMENT '商品id',`spec_content` TEXT COMMENT '规格信息',`spec_img` VARCHAR(500) DEFAULT NULL COMMENT '商品规格图片',`old_price` DECIMAL(10,2) DEFAULT NULL COMMENT '原价',`new_price` DECIMAL(10,2) DEFAULT NULL COMMENT '现价',`stock` INT(11) DEFAULT NULL COMMENT '库存',`sales_num` INT(11) DEFAULT '0' COMMENT '已售件数或是已兑换件数',`integer_count` INT(11) DEFAULT NULL COMMENT '兑换需要的积分数',`integer_price` DECIMAL(10,2) DEFAULT NULL COMMENT '积分商品价格',`create_time` DATETIME DEFAULT NULL COMMENT '创建时间',`update_time` DATETIME DEFAULT NULL COMMENT '修改时间',`seller_id` INT(11) DEFAULT NULL COMMENT '商家id,后台商品录入时添加商家id',PRIMARY KEY (`id`)) ENGINE=INNODB AUTO_INCREMENT=23 DEFAULT CHARSET=utf8;/*Data for the table `goods_spec` */INSERT INTO `goods_spec`(`id`,`goods_id`,`spec_content`,`spec_img`,`old_price`,`new_price`,`stock`,`sales_num`,`integer_count`,`integer_price`,`create_time`,`update_time`,`seller_id`) VALUES (1,1,'[{"specKeyId":2,"specValueId":3},{"specKeyId":1,"specValueId":2}]','粉色图片','119.00','109.25',25,50,NULL,NULL,'2020-09-02 13:42:31',NULL,1),(2,2,'[{"specKeyId":2,"specValueId":3},{"specKeyId":1,"specValueId":1}]','灰色图片','119.00','109.00',20,5,NULL,NULL,'2020-09-02 13:42:33',NULL,1),(3,3,'[{"specKeyId":2,"specValueId":4},{"specKeyId":1,"specValueId":2}]','珊瑚/灰色图片','129.00','127.00',30,8,NULL,NULL,'2020-09-02 13:44:17',NULL,1),(4,4,'[{"specKeyId":2,"specValueId":4},{"specKeyId":1,"specValueId":2}]','水蓝/灰色图片','139.00','135.00',20,8,NULL,NULL,'2020-09-02 13:45:08',NULL,1),(5,5,'{颜色分类":"黑色NNN07010OS【满2件顺丰包邮】"}','黑色图片','69.00','64.00',20,5,5000,NULL,'2020-09-02 13:46:10',NULL,1),(6,2,'{"颜色分类":"蓝绿色/15kg（所有女生，买它）"}','蓝绿图片','39.90','35.22',5,25,NULL,NULL,'2020-09-02 13:48:30',NULL,1),(7,2,'{"颜色分类":"玄黑色/60kg（天阶训练）"}','玄黑图片','59.00','58.00',25,9,NULL,NULL,'2020-09-02 13:49:42',NULL,1),(8,3,'{"颜色分类":"加厚防爆-【粉色】"}','粉色图片','93.80','90.00',30,2,NULL,NULL,'2020-09-02 14:40:19',NULL,1),(9,4,'{"颜色分类":"3米加长版20磅天青蓝【推荐健身女士】"}','青蓝图片','119.28','110.28',85,94,NULL,NULL,'2020-09-02 14:42:19',NULL,1),(10,6,'{"颜色分类":"【限量抢买送固定扣】两根-长80cm【159-165cm选择】"}','规格图片','33.50','32.59',50,8,NULL,NULL,'2020-09-02 15:10:55',NULL,1),(11,7,'{"颜色分类":"独立按摩瑜伽柱（45cm）天青*赠收纳包"}','天青图片','129.00','30.25',50,2,6000,NULL,'2020-09-02 15:13:42',NULL,1),(12,2,'测试新增规格00','规格图片','19.25','20.85',20,NULL,20,'25.98','2020-09-05 15:47:13',NULL,2),(21,14,'[{"specKeyId":1,"specValueId":21},{"specKeyId":10,"specValueId":25}]','商品图片','25.98','36.98',25,0,0,NULL,'2020-09-07 15:53:20',NULL,2),(22,14,'[{"specKeyId":1,"specValueId":22},{"specKeyId":10,"specValueId":24}]','商品图片','29.68','28.56',50,0,NULL,NULL,'2020-09-07 16:19:54',NULL,2);

规格表(其他字段已忽略):

规格项表(其他字段已忽略):

7.逻辑层数据处理:

// 查询购物车列表List<GoodsCartReturnVo> goodsCartNew = goodsCartMapper.findReturnGoodsCart("155984905041578");System.out.println(goodsCartNew); for (GoodsCartReturnVo goodsCartNewVo : goodsCartNew) { List<GoodsSpecInfo> goodsSpecInfoList = goodsCartNewVo.getGoodsSpecInfoList(); for (GoodsSpecInfo goodsSpecInfo : goodsSpecInfoList) { //ArrayList<List<SpecContentInfo>> specContentInfoArrayList = new ArrayList<>(); String specContent = goodsSpecInfo.getSpecContent(); // 将json字符串转化成json对象集合 List<SpecContentVo> SpecContentVos = JSONArray.parseArray(specContent, SpecContentVo.class); // 根据规格id以及规格项id获取对应的名称 List<SpecContentInfo> specContentInfo = goodsCartMapper.findSpecContentInfo(SpecContentVos); goodsSpecInfo.setSpecContentInfos(specContentInfo); // 清空json格式的规格id goodsSpecInfo.setSpecContent(""); } }System.out.println(JSONObject.toJSONString(goodsCartNew));

8.说明:由于goods_spec中的spec_content中存储的是规格id与规格项id的json字符串,所以需要调用findSpecContentInfo方法将对应的名称查询出来.

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