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+笔记
+
+```
+spu: 一种规格
+sku: 一种单位,唯一表示符
+```
+
+代码
+
+```mysql
+CREATE DATABASE x CHARSET utf8;
+use x;
+/*==============================================================*/
+/* DBMS name:      MySQL 5.0                                    */
+/* Created on:     2023-09-21 11:22:58                          */
+/*==============================================================*/
+
+
+drop table if exists commodity;
+
+drop table if exists middle;
+
+drop table if exists property;
+
+drop table if exists specification;
+
+drop table if exists value;
+
+/*==============================================================*/
+/* Table: commodity                                             */
+/*==============================================================*/
+create table commodity
+(
+   co_id                int not null auto_increment,
+   co_name              varchar(30) not null,
+   introductory         varchar(100) not null,
+   primary key (co_id)
+);
+INSERT into commodity VALUES (1,'华为手机Mate 60 Pro','遥遥领先'),
+(2,'Redmi K60 至尊版 天玑9200+','小米配天玑越用越懵逼');
+
+/*==============================================================*/
+/* Table: middle                                                */
+/*==============================================================*/
+create table middle
+(
+   m_id                 int not null auto_increment,
+   sp_id                int,
+   p_id                 int,
+   v_id                 int,
+   primary key (m_id)
+);
+INSERT into middle VALUES(1,1,1,1),(2,1,2,5),(3,2,1,2),(4,2,2,8),(5,3,1,3),(6,3,2,6),(7,4,1,4),(8,4,2,7);
+
+/*==============================================================*/
+/* Table: property                                              */
+/*==============================================================*/
+create table property
+(
+   p_id                 int not null auto_increment,
+   p_name               varchar(10) not null,
+   primary key (p_id)
+);
+
+INSERT into property VALUES(1,'颜色'),(2,'存储版本');
+/*==============================================================*/
+/* Table: specification                                         */
+/*==============================================================*/
+create table specification
+(
+   sp_id                int not null auto_increment,
+   co_id                int,
+   sp_title             varchar(50) not null,
+   price                decimal(9,2) not null,
+   inventory            varchar(10) not null,
+   primary key (sp_id)
+);
+
+INSERT into specification VALUES (1,1,'华为（HUAWEI）旗舰手机 Mate 60 Pro 12GB+512GB ',6999,500),(2,1,'华为（HUAWEI）旗舰手机 Mate 60 Pro 12GB+1TB',7999,300),(3,2,' Redmi K60 至尊版 天玑9200+ 16GB+512GB',2999,5000),(4,2,' Redmi K60 至尊版 天玑9200+ 16GB+1TB',3299,5000);
+
+/*==============================================================*/
+/* Table: value                                                 */
+/*==============================================================*/
+create table value
+(
+   v_id                 int not null auto_increment,
+   v_name               varchar(20) not null,
+   primary key (v_id)
+);
+
+INSERT into value VALUES(1,'雅川青'),(2,'鸭蛋黑'),(3,'晴雪'),(4,'耀眼的黑'),(5,'12GB+512GB'),(6,'16GB+512GB'),(7,'16GB+1TB'),(8,'12GB+1TB');
+
+
+alter table middle add constraint FK_Relationship_2 foreign key (sp_id)
+      references specification (sp_id) on delete restrict on update restrict;
+
+alter table middle add constraint FK_Relationship_3 foreign key (p_id)
+      references property (p_id) on delete restrict on update restrict;
+
+alter table middle add constraint FK_Relationship_4 foreign key (v_id)
+      references value (v_id) on delete restrict on update restrict;
+
+alter table specification add constraint FK_belong_pp foreign key (co_id)
+      references commodity (co_id) on delete restrict on update restrict;
+
+SELECT * from commodity c INNER JOIN specification s ON c.co_id=s.co_id INNER JOIN middle m ON  s.sp_id=m.sp_id INNER JOIN property  p ON m.p_id=p.p_id INNER JOIN value v on m.v_id=v.v_id where v.v_name='雅川青' OR c.co_name='华为手机Mate 60 Pro';
+```
+