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не съм сигурен в форейн ключовете това с което се референсват

create database online_magazin_db;
use online_magazin_db;

create table customers (
    customer_id int auto_increment primary key,
    name varchar(100) not null,
    email varchar(100) unique not null,
    address varchar(200),
    phone varchar(20)
);

create table categories (
    category_id int auto_increment primary key,
    category_name varchar(100) not null
);

create table suppliers (
    supplier_id int auto_increment primary key,
    supplier_name varchar(100) not null,
    contact varchar(100),
    supplier_address varchar(200)
);

create table products (
    product_id int auto_increment primary key,
    product_name varchar(100) not null,
    price decimal(10,2) not null,
    quantity int not null,
    category_id int,
    supplier_id int,
    foreign key (category_id) references categories(category_id),
    foreign key (supplier_id) references suppliers(supplier_id)
);

create table orders (
    order_id int auto_increment primary key,
    customer_id int,
    order_date date not null,
    total_amount decimal(10,2),
    foreign key (customer_id) references customers(customer_id)
);

create table order_items (
    order_item_id int auto_increment primary key,
    order_id int,
    product_id int,
    quantity int not null,
    price decimal(10,2) not null,
    foreign key (order_id) references orders(order_id),
    foreign key (product_id) references products(product_id)
);

create table payments (
    payment_id int auto_increment primary key,
    order_id int,
    payment_date date not null,
    amount decimal(10,2) not null,
    method enum('cash','card','online') not null,
    foreign key (order_id) references orders(order_id)
);