Question

我想制作一个声明系统。但我弄乱了数据库设计部分。

系统将拥有无限的类别及其项目，因此每个类别都会有奇怪的属性

例如，汽车有型号，贸易，制造日期，颜色，齿轮类型。。。还有更多

另一个例子房地产有门数，花园，dublex三重类型，多少浴，多少厨房

另一个可以是电子的，它有百万像素，千兆字节，保修，分辨率，尺寸，发货。。。

所以我如何将这些数据收集到一起可能一些对象会有类似的属性，例如大多数项目都必须有一个制造商日期，以便我如何使用这些数据？架构怎么样？

Sercan Virlan

Answer 1

请注意，这是一个非常模糊的问题，所以我尽力回答：）

注意：有很多更好的方法可以做到这一点，我可以问你为什么这样做，但下面的方法应该可以实现你想要的！

以下是3个表格：

CREATE TABLE `object` (
`id` INTEGER NOT NULL AUTO_INCREMENT ,
`category` INTEGER NOT NULL ,
`name` VARCHAR(100) NOT NULL ,
PRIMARY KEY (`id`)
);

CREATE TABLE `properties` (
`id` INTEGER NOT NULL AUTO_INCREMENT ,
`objectid` INTEGER NOT NULL ,
`property_key` VARCHAR(100) NOT NULL ,
`property_value` MEDIUMTEXT NOT NULL ,
PRIMARY KEY (`id`)
);

CREATE TABLE `category` (
`id` INTEGER NOT NULL AUTO_INCREMENT ,
`name` VARCHAR(100) NOT NULL ,
PRIMARY KEY (`id`)
);

现在让我们添加一些假装数据：

INSERT INTO category VALUES ("","CAR");
INSERT INTO category VALUES ("","REALESTATE");
INSERT INTO category VALUES ("","ELECTRONIC");
INSERT INTO object VALUES ("",1,"98 CAMERO");
INSERT INTO object VALUES ("",1,"06 PRIUS");
INSERT INTO object VALUES ("",2,"A House Someplace");
INSERT INTO object VALUES ("",3,"iPod Touch");
INSERT INTO object VALUES ("",3,"iPhone");
INSERT INTO object VALUES ("",3,"Zune");
INSERT INTO properties VALUES ("",1,"color","red");
INSERT INTO properties VALUES ("",1,"doors","4");
INSERT INTO properties VALUES ("",1,"engine","v6");
INSERT INTO properties VALUES ("",2,"engine","electric");
INSERT INTO properties VALUES ("",2,"doors","4");
INSERT INTO properties VALUES ("",2,"color","blue");
INSERT INTO properties VALUES ("",6,"video-playback","true");
INSERT INTO properties VALUES ("",4,"video-playback","true");
INSERT INTO properties VALUES ("",5,"video-playback","true");
INSERT INTO properties VALUES ("",6,"manufacturer","microsoft");
INSERT INTO properties VALUES ("",5,"manufacturer","apple");
INSERT INTO properties VALUES ("",4,"manufacturer","apple");

现在，我们的数据应该是这样的。

mysql> select * from object;
+----+----------+-------------------+
| id | category | name              |
+----+----------+-------------------+
|  1 |        1 | 98 CAMERO         | 
|  2 |        1 | 06 PRIUS          | 
|  3 |        2 | A House Someplace | 
|  4 |        3 | iPod Touch        | 
|  5 |        3 | iPhone            | 
|  6 |        3 | Zune              | 
+----+----------+-------------------+
6 rows in set (0.00 sec)

mysql> select * from category;
+----+-------------+
| id | name        |
+----+-------------+
|  1 | CAR         | 
|  2 | REALESTATE  | 
|  3 | ELECTRONICS | 
+----+-------------+
3 rows in set (0.00 sec)

mysql> select * from properties;
+----+----------+----------------+----------------+
| id | objectid | property_key   | property_value |
+----+----------+----------------+----------------+
|  1 |        1 | color          | red            | 
|  2 |        1 | doors          | 4              | 
|  3 |        1 | engine         | v6             | 
|  4 |        2 | engine         | electric       | 
|  5 |        2 | doors          | 4              | 
|  6 |        2 | color          | blue           | 
|  7 |        6 | video-playback | true           | 
|  8 |        4 | video-playback | true           | 
|  9 |        5 | video-playback | true           | 
| 10 |        6 | manufacturer   | microsoft      | 
| 11 |        5 | manufacturer   | apple          | 
| 12 |        4 | manufacturer   | apple          | 
+----+----------+----------------+----------------+
12 rows in set (0.00 sec)

您可以在这些表中添加无限数量的类别，无限数量的属性和无限数量的对象。

现在一起加入他们：

mysql> SELECT * FROM object 
    ->   LEFT JOIN category ON object.category = category.id
    ->   LEFT JOIN properties ON properties.objectid = object.id;
+----+----------+-------------------+------+-------------+------+----------+----------------+----------------+
| id | category | name              | id   | name        | id   | objectid | property_key   | property_value |
+----+----------+-------------------+------+-------------+------+----------+----------------+----------------+
|  1 |        1 | 98 CAMERO         |    1 | CAR         |    1 |        1 | color          | red            | 
|  1 |        1 | 98 CAMERO         |    1 | CAR         |    2 |        1 | doors          | 4              | 
|  1 |        1 | 98 CAMERO         |    1 | CAR         |    3 |        1 | engine         | v6             | 
|  2 |        1 | 06 PRIUS          |    1 | CAR         |    4 |        2 | engine         | electric       | 
|  2 |        1 | 06 PRIUS          |    1 | CAR         |    5 |        2 | doors          | 4              | 
|  2 |        1 | 06 PRIUS          |    1 | CAR         |    6 |        2 | color          | blue           | 
|  3 |        2 | A House Someplace |    2 | REALESTATE  | NULL |     NULL | NULL           | NULL           | 
|  4 |        3 | iPod Touch        |    3 | ELECTRONICS |    8 |        4 | video-playback | true           | 
|  4 |        3 | iPod Touch        |    3 | ELECTRONICS |   12 |        4 | manufacturer   | apple          | 
|  5 |        3 | iPhone            |    3 | ELECTRONICS |    9 |        5 | video-playback | true           | 
|  5 |        3 | iPhone            |    3 | ELECTRONICS |   11 |        5 | manufacturer   | apple          | 
|  6 |        3 | Zune              |    3 | ELECTRONICS |    7 |        6 | video-playback | true           | 
|  6 |        3 | Zune              |    3 | ELECTRONICS |   10 |        6 | manufacturer   | microsoft      | 
+----+----------+-------------------+------+-------------+------+----------+----------------+----------------+
13 rows in set (0.00 sec)

我希望这是您正在寻找的，它是一个无限可扩展的解决方案，但如果数据库因繁重的工作负载而变得非常繁重，那么它可能会因为其设计而变慢。

Mysql数据库设计复杂的购物目录部分

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