如何设计处理订单、订单项、退货、退款、换货的数据库？

Question

互联网上的大多数问题都集中在 Order、OrderItem。设计一个全面处理在线零售各个方面（订单、订单项、退货、退款、换货）的数据库几乎没有问题。

我基本上只知道这个数据模型。

产品（产品 ID、名称等）
订单（订单 ID、日期、总成本等）
订单项（订单 ID、产品 ID、数量、单价等）

基于以上结构，我如何管理退货、退款、换货？

我注意到，当我在超市退换货时，那里的工作人员会重新生成一张新发票。这是他们处理退货、退款、换货的方式吗？

Answer 1

• (F table.column) 表示指向table.column的外键
• (P) 表示主键
• (U) 表示唯一密钥

这是一些表格和示例数据...

addresses
    id          unsigned int(P)
    line1       varchar(50)
    line2       varchar(50) // Allow NULL
    city_id     unsigned int(F cities.id)
    zip         varchar(6) // 5 digits for US and MX, 6 characters (X9X9X9) for CA
    zip4        char(4) // Allow NULL

+----+-----------------+-------+---------+--------+------+
| id | line1           | line2 | city_id | zip    | zip4 |
+----+-----------------+-------+---------+--------+------+
|  1 | 123 Main Street | Apt A |      17 | 92101  | 1234 |
|  2 | 345 East Street | NULL  |      25 | T1X0L3 | NULL |
| .. | ............... | ..... | ....... | ...... | .... |
+----+-----------------+-------+---------+--------+------+

cities
    id                  unsigned int(P)
    state_id            unsigned int(F states.id)
    name                varchar(50)
    ...

+----+----------+-----------+-----+
| id | state_id | name      | ... |
+----+----------+-----------+-----+
| .. | ........ | ......... | ... |
| 17 |      130 | San Diego | ... |
| .. | ........ | ......... | ... |
| 25 |       14 | Calgary   | ... |
| .. | ........ | ......... | ... |
+----+----------+-----------+-----+

参见ISO 3166-1

countries
    id              char(2)(P)
    iso3            char(3)(U)
    iso_num         char(3)(U)
    name            varchar(45)(U)

+----+------+---------+---------------+
| id | iso3 | iso_num | name          |
+----+------+---------+---------------+
| .. | .... | ....... | ............. |
| CA | CAN  | 124     | Canada        |
| .. | .... | ....... | ............. |
| MX | MEX  | 484     | Mexico        |
| .. | .... | ....... | ............. |
| US | USA  | 840     | United States |
| .. | .... | ....... | ............. |
+----+------+---------+---------------+

请参阅PHP 的 crypt() 函数来对密码进行哈希处理。

customers
    id              unsigned int(P)
    first_name      varchar(50)
    middle_name     varchar(50) // Allow NULL
    last_name       varchar(50)
    email           varchar(255)
    username        varchar(32)
    password        varbinary(255) // hashed
    ...

+----+------------+-------------+-----------+----------------------------+-----------+----------+-----+
| id | first_name | middle_name | last_name | email                      | username  | password | ... |
+----+------------+-------------+-----------+----------------------------+-----------+----------+-----+
|  1 | John       | Quincy      | Public    | jqp@privacy.com            | johnqball | xxxxxxxx | ... |
|  2 | Jane       | NULL        | Doe       | ladyinred@chrisdeburgh.com | janeykins | xxxxxxxx | ... |
| .. | .......... | ........... | ......... | .......................... | ......... | .......  | ... |
+----+------------+-------------+-----------+----------------------------+-----------+----------+-----+

customers_addresses
    id              unsigned int(P)
    customer_id     unsigned int(F customers.id)
    address_id      unsigned int(F addresses.id)

orders
    id                  unsigned int(P)
    customer_id         unsigned int(F customers.id)
    bill_address_id     unsigned int(F addresses.id)
    ship_address_id     unsigned int(F addresses.id)
    created             datetime
    shipped             datetime
    ...

+----+-------------+-----------------+-----------------+---------------------+---------------------+-----+
| id | customer_id | bill_address_id | ship_address_id | created             | shipped             | ... |
+----+-------------+-----------------+-----------------+---------------------+---------------------+-----+
|  1 | 1           | 1               | 1               | 2012-12-31 23:59:59 | 2013-01-01 00:00:00 | ... |
+----+-------------+-----------------+-----------------+---------------------+---------------------+-----+

orders_products
    id              unsigned int(P)
    order_id        unsigned int(F orders.id)
    product_id      unsigned int(F products.id)
    quantity        unsigned int
    unit_price      double
    ...

+----+----------+------------+----------+------------+-----+
| id | order_id | product_id | quantity | unit_price | ... |
+----+----------+------------+----------+------------+-----+
|  1 | 1        | 1          | 1        | 12.34      | ... |
|  2 | 1        | 2          | 13       | 1.78       | ... |
| .. | ........ | .......... | ........ | .......... | ... |
+----+----------+------------+----------+------------+-----+

products
    id                  unsigned int(P)
    name                varchar(50)
    price               double
    ...

+----+----------+-------+-----+
| id | name     | price | ... |
+----+----------+-------+-----+
|  1 | Widget 1 | 12.34 | ... |
|  2 | Widget 2 | 1.78  | ... |
| .. | ........ | ..... | ... |
+----+----------+-------+-----+

returns
    id                      unsigned int(P)
    order_product_id        unsigned int(F orders_products.id)
    quantity                unsigned int
    ...

+----+------------------+----------+-----+
| id | order_product_id | quantity | ... |
+----+------------------+----------+-----+
|  1 | 1                | 1        | ... |
| .. | ................ | ........ | ... |
+----+------------------+----------+-----+

参见ISO 3166-2

states
    id              unsigned int(P)
    country_id      char(2)(F countries.id)
    code            char(2) // AB, AL, NL, etc.
    name            varchar(50) // Alberta, Alabama, Nuevo Leon, etc.
    ...

+-----+------------+------+------------+-----+
| id  | country_id | code | name       | ... |
+-----+------------+------+------------+-----+
| ... | .......... | .... | .......... | ... |
|  14 | CA         | AB   | Alberta    | ... |
| ... | .......... | .... | .......... | ... |
|  72 | MX         | CH   | Chiapas    | ... |
| ... | .......... | .... | .......... | ... |
| 130 | US         | CA   | California | ... |
| ... | .......... | .... | .......... | ... |
+-----+------------+------+------------+-----+

退货、退款和换货都是真正的退货——客户正在退回产品。你如何处理它取决于你的业务规则......