Mysql 如何在配方表中添加自参考以允许子配方?
我想要一个包含配料列表和子配方列表的表格,例如:Mysql 如何在配方表中添加自参考以允许子配方?,mysql,sql,database,Mysql,Sql,Database,我想要一个包含配料列表和子配方列表的表格,例如: #recipe yellow lemon juice Ingredient unit cost quantity 1.Yellow lemon Kg 1.7 1 2.--suppose it has ingredient 2 3.--suppose it has ingredient 3 #recipe mayonnaise Ingredient unit cost qu
#recipe yellow lemon juice
Ingredient unit cost quantity
1.Yellow lemon Kg 1.7 1
2.--suppose it has ingredient 2
3.--suppose it has ingredient 3
#recipe mayonnaise
Ingredient unit cost quantity
1.olive oil Lt $2.5 1
2.egg Kg $2.5 0.12
3.mustard Kg $1.59 0.01
4.salt Kg $.9 0.01
5.RECIPE yellow lemon juice Lt $1.9 1 ------------this one is a recipe
我怎么知道蛋黄酱配方使用的是黄色柠檬汁配方?
我有以下内容,但不知道如何在配方表中允许子配方
现在可能是这样的,我有3个食谱A、B、C
,食谱A
有几种成分,但也包括食谱B
和C
我可能会补充一点:
Create table dressing
(
dressing_id int,
recipe_id int,
constraint pk_dressing primary key (dressing_id, recipe_id),
constraint fk_recipe foreign key (recipe_id) references recipe(recipe_id),
constraint fk_dressing foreign key (dressing_id) references recipe(recipe_id)
);
我还想在蛋黄酱里加些糖和醋……:) 让我们假设调味品将是主桌,他们的一排将被食谱填充,所以在这种情况下,我会有两排柠檬汁食谱和有毒蛋黄酱,对吗?一点也不。您可以像往常一样在配方表中填写配方。但是,当一个食谱需要另一个食谱时,你可以用蛋黄酱食谱(必须在食谱表中)填满调味品表。食谱和SQL是令人困惑的lol
Create table dressing
(
dressing_id int,
recipe_id int,
constraint pk_dressing primary key (dressing_id, recipe_id),
constraint fk_recipe foreign key (recipe_id) references recipe(recipe_id),
constraint fk_dressing foreign key (dressing_id) references recipe(recipe_id)
);