mysql - 如何使用 N :M relationship in MySQL? 创建表

Question

假设我有这两个表:Store 和 Product。我希望我的商店有一个产品列表。我该怎么做？

create table store(
id int unsigned not null auto_increment,
store_name varchar(30) not null,
product_list_FK int unsigned not null,
primary key(id)
);

create table product(
id int unsigned not null auto_increment,
product_name varchar(30) not null,
price float not null,
primary key(id)
);

我开始了类似的事情，但我不知道如何结束，你们能帮帮我吗？

Answer 1

多对一(产品只能有一个商店)

create table store(
    id int unsigned not null auto_increment,
    store_name varchar(30) not null,
    primary key(id)
);

Query OK, 0 rows affected (0.02 sec)

create table product(
    id int unsigned not null auto_increment,
    store_id int unsigned not null,
    product_name varchar(30) not null,
    price float not null,
    primary key(id),
    constraint product_store foreign key (store_id) references store(id)
);

Query OK, 0 rows affected (0.02 sec)

多对多(产品可以在很多商店)

create table store(
    id int unsigned not null auto_increment,
    store_name varchar(30) not null,
    primary key(id)
);

Query OK, 0 rows affected (0.04 sec)

create table product(
    id int unsigned not null auto_increment,
    store_id int unsigned not null,
    product_name varchar(30) not null,
    price float not null,
    primary key(id)
);

Query OK, 0 rows affected (0.01 sec)

create table product_store (
    product_id int unsigned not null,
    store_id int unsigned not null,
    CONSTRAINT product_store_store foreign key (store_id) references store(id),
    CONSTRAINT product_store_product foreign key (product_id) references product(id),
    CONSTRAINT product_store_unique UNIQUE (product_id, store_id)
)

Query OK, 0 rows affected (0.02 sec)