数据库设计链接2个表到1链接到几个

Question

我目前有 3个主要表格 animal, food and medicine。

从动物表中我得到表格：

1. 物种（猫，狗，鸟，鱼......）
2. 尺寸（小，中，大，大...）
3. 年龄（小狗，年轻人，老...）
4. 颜色（棕色，黑色，灰色......）

我想存储给予动物的药物和食物的有用数据 但我不知道如何链接这些数据，以下方法是否可接受或我应该添加或删除什么？

我的主要问题是复合键的正确性以及在查询中检索数据的方式......

动物

idAn SEX AGE COMMENT           SPECIES color  HAIR   SIZE
----------------------------------------------------------
1     M   1  without ear         1      1     LONG    1
2     F   2  blue eyed all gray  2      2     short   1

物种

id name
-------
1  dog
2  cat
3  bird
4  fish
5  reptile
6  mouse  
7  other

年龄

id name
-------
1 puppy
2 young
3 adult
4 old

颜色

id  name
--------
1  black
2  gray
3  gold
4  green
5  red
6  brown

大小

id  name
--------
1  small
2  medium
3  large
4  big

食品

id name      label      
-------------------
1  sardine     so 
2  croquettes  dogchauw   
3  chicken     sirw
4  whiskas     whiskas  

food_Animal

idFood  idAnimal   quantity timesPerDay lastFood    LastWater
----------------------------------------------------------------------
2             1    70gr      3        12-12-12   12-12-12  
3             2    80gr      4        12-11-12   12-11-12

和上面的药物一样。

可以做什么或如何在MySQL中使用它

我开始时喜欢

CREATE TABLE IF NOT EXISTS ANIMAL(
    idAn    int(3) NOT NULL AUTO_INCREMENT,
    sex     int(2) NOT NULL ,
    age     int(2) NOT NULL ,
    comment varchar(50)  ,                  
        species int(2) NOT NULL , 
    color   int(2) NOT NULL ,
        hair    varchar(50)     ,                   
        size    int(2) NOT NULL ,
    PRIMARY KEY (idAn)
) ENGINE=MyISAM DEFAULT CHARSET=utf8 AUTO_INCREMENT=0;

Answer 1

/* Create a table with 2 fields, Entity and Name. Primary key is BOTH fields (as we know that Entity->Name will be a unique value) */
CREATE TABLE master_lookup (
  Entity nvarchar(10) not null,
  Name nvarchar(20) not null,
  primary key(Entity, Name)
);

/* Insert some data! */
INSERT INTO master_lookup VALUES 
('Species', 'Dog'),
('Species', 'Cat'), 
('Species', 'Bird'),
('Color', 'Black'),
('Color', 'Brown');

/* Let's have a look... */
SELECT * FROM master_lookup;
 Entity  | Name
----------------
 Species | Dog
 Species | Cat
 Species | Bird
 Color   | Black
 Color   | Brown

/* Et voila. One lookup table, ID numbers need not apply. Let's assume you have a form that will populate the Animal table with a list of species for the user to pick from. The source of the list is easy: */
SELECT Name FROM master_lookup WHERE Entity = 'Species';

/* Your INSERT query into Animal will look like this (let's say they're entering a small brown long-haired dog): */
INSERT INTO Animal ('M', 11, 'a comment', 'Dog', 'Brown', 'Long', 'Small');

/* And now when you SELECT from the animal table... */
SELECT * FROM Animal

idAn SEX AGE COMMENT           SPECIES color  HAIR   SIZE
----------------------------------------------------------
1     M   11  a comment         Dog    Brown  Long   Small

/* Look ma! No joins! Which means your query is much simpler and much faster! Yay! */