【发布时间】：2014-01-27 09:58:08
【问题描述】：
我正在尝试创建一个库存管理架构，我可以在其中跟踪与产品相关的各种选项的库存。一个产品可能有任意数量的选项，但在本例中，我将使用“尺寸”和“颜色”选项。
我想出了三个表：
CREATE TABLE shop_options (
option_id INTEGER UNSIGNED NOT NULL AUTO_INCREMENT,
option_name VARCHAR(40) NOT NULL,
PRIMARY KEY (option_id)
);
INSERT INTO shop_options (option_id, option_name) VALUES (1, 'Size');
INSERT INTO shop_options (option_id, option_name) VALUES (2, 'Color');
CREATE TABLE shop_option_properties (
prop_id INTEGER UNSIGNED NOT NULL AUTO_INCREMENT,
prop_name VARCHAR(40) NOT NULL,
PRIMARY KEY (prop_id)
);
INSERT INTO shop_option_values (prop_id, prop_name) VALUES (1, 'XS');
INSERT INTO shop_option_values (prop_id, prop_name) VALUES (2, 'S');
INSERT INTO shop_option_values (prop_id, prop_name) VALUES (3, 'M');
INSERT INTO shop_option_values (prop_id, prop_name) VALUES (4, 'L');
INSERT INTO shop_option_values (prop_id, prop_name) VALUES (5, 'XL');
INSERT INTO shop_option_values (prop_id, prop_name) VALUES (6, 'White');
INSERT INTO shop_option_values (prop_id, prop_name) VALUES (7, 'Black');
INSERT INTO shop_option_values (prop_id, prop_name) VALUES (8, 'Red');
INSERT INTO shop_option_values (prop_id, prop_name) VALUES (9, 'Green');
INSERT INTO shop_option_values (prop_id, prop_name) VALUES (10, 'Blue');
CREATE TABLE shop_product_options (
product_id INTEGER UNSIGNED NOT NULL,
option_id INTEGER UNSIGNED NOT NULL,
prop_id INTEGER UNSIGNED DEFAULT NULL,
surcharge DECIMAL(7,2) NOT NULL DEFAULT '0.00',
stock INTEGER UNSIGNED DEFAULT NULL, /* NULL = stock is not limited */
FOREIGN KEY (product_id)
REFERENCES shop_products(product_id),
FOREIGN KEY (option_id)
REFERENCES shop_options(option_id),
FOREIGN KEY (prop_id)
REFERENCES shop_option_properties(prop_id)
);
我已经确定这行不通，因为我的库存中可能有“总共十个小物品”和“总共十个白色物品”，但没有“总共十个白色小物品”的库存。
如何改进我的架构以正确跟踪产品可能具有的每个选项的库存？
编辑
我将以下更新包括在内，以供与我遇到同样问题的其他人使用。一开始我发现接受的答案很难理解。基本上，我可以通过对shop_product_options 表进行以下修改来保留上面的架构：
CREATE TABLE shop_product_options (
po_id INTEGER UNSIGNED NOT NULL AUTO_INCREMENT,
product_id INTEGER UNSIGNED NOT NULL,
option_id INTEGER UNSIGNED NOT NULL,
prop_id INTEGER UNSIGNED NOT NULL,
surcharge DECIMAL(7,2) UNSIGNED NOT NULL DEFAULT '0.00',
stock INTEGER UNSIGNED DEFAULT NULL,
PRIMARY KEY (po_id, product_id, option_id, prop_id),
FOREIGN KEY (product_id)
REFERENCES shop_products(product_id),
FOREIGN KEY (option_id)
REFERENCES shop_options(option_id),
FOREIGN KEY (prop_id)
REFERENCES shop_option_properties(prop_id)
);
将添加的po_id 和组合键作为主键，我现在可以插入和提取“分组”数据，如下所示：
INSERT INTO shop_products (product_id, title) VALUES (1, 'Womens Shoe');
INSERT INTO shop_product_options (po_id, product_id, option_id, prop_id, surcharge, stock)
VALUES (1, 1, 1, 3, '0.00', 10);
INSERT INTO shop_product_options (po_id, product_id, option_id, prop_id, surcharge, stock)
VALUES (1, 1, 2, 9, '0.50', 20);
INSERT INTO shop_product_options (po_id, product_id, option_id, prop_id, surcharge, stock)
VALUES (2, 1, 1, 5, '1.00', 30);
INSERT INTO shop_product_options (po_id, product_id, option_id, prop_id, surcharge, stock)
VALUES (2, 1, 2, 9, '0.75', 40);
SELECT t1.po_id, t2.title, t3.option_name, t4.prop_name, t1.surcharge, t1.stock FROM shop_product_options AS t1
JOIN shop_products AS t2 ON t1.product_id = t2.product_id
JOIN shop_options AS t3 ON t1.option_id = t3.option_id
JOIN shop_option_properties AS t4 ON t1.prop_id = t4.prop_id
WHERE t1.product_id = 1 ORDER BY t1.po_id ASC;
这导致了 M 码绿色女鞋和 XL 码绿色女鞋，每种鞋的尺码和颜色都有不同的库存数量。
【问题讨论】：
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你可以从here开始。
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@ChristianMark 你能说得更具体点吗？我浏览了该页面上的一半链接，但尚未找到与我的问题相关的链接。
标签： mysql database database-design schema relational-database