[英]Relational database structure - best practice?
Situation: I am a bit of a newbie with databases, and have just plugged MySQLdb into python (at great length). 情况:我是数据库的新手,并且刚刚将MySQLdb插入python(很长)。 I am looking for basic tips in terms of how to structure my data tables, when to break off into a new table, etc.
我正在寻找有关如何构造数据表,何时分解为新表等方面的基本技巧。
Example: Say I'm looking at pet owners, their pets, and their pets' toys. 示例:假设我正在看宠物主人,他们的宠物和他们的宠物玩具。 I'm ultimately interested in the properties of the toys.
我最终对玩具的属性感兴趣。
Pet owner 1: has 3 pets: each pet has 5 toys: each toy has unique properties.
Pet owner 2: has 2 pets: each pet has 4 toys: each toy has unique properties.
Question: Should this stay as one table, or should I have several tables linking owners with pets, then pets with toys, etc.? 问题:这应该是一张桌子,还是我应该有几张桌子将主人与宠物联系起来,然后将宠物与玩具联系起来,等等? Is there a hard and fast rule?
有硬性规定吗?
Thanks in advance. 提前致谢。
I would think of each object as it's own table, then look for one to many relationships and give them their own table, so something like this: 我会将每个对象都视为自己的表,然后查找一对多关系并为其提供自己的表,因此如下所示:
PetOwner 宠物主人
Column
------
OwnerId --primary key
FirstName
LastName
--any other info you want to track on the owner
OwnersPets 主人宠物
Column
------
OwnerId --composite primary key
PetId --composite primarykey
--any other info relating to the ownership
Pets 宠物用品
Column
------
PetId --primarykey
PetName
--any other pet properties (color, birthdate, etc...)
PetsToys 宠物玩具
Column
------
PetId --composite primary key
ToyId --composite primarykey
--any other info relating to the pets ownership of the toy (dateOfIntroduction maybe)
Toys 玩具
Column
------
ToyId--primarykey
Manufacturer
Type
Cost
DateOfPurchase
--any other toy properties
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