CODEWITHSUNDEEP
mysqlsqlruby-on-railsrubyerd
Raj
Raj

Reputation: 45

Relationship with many to many

I am trying to get a basic rails application running that helps capture the nutritional information of each food item from a list of food items. The nutritional information is stored per ingredient and calculated as the sum of individual ingredients.

Here is what I have so far:

Have two models Food and Ingredient. Each Food has many Ingredients and each Ingredient is used in many Food. The way I want to fix this is to break up the many-to-many with a table in between say Recipe which has the pk of Food and pk Ingredient. But my problem is that a Recipe can have many ingredients and an ingredient has many recipes. How do i split these two tables the best way so I can capture a food item and its list of ingredients? Or is there a better way to do the whole thing?

Say for the purposes of example Food has name, description and Ingredient has name, calories, nutrients.

Upvotes: 1

Views: 182

Answers (1)

Nermin
Nermin

Reputation: 6100

You need has_many_through association.

You will organize like:

class Food < ActiveRecord::Base
  has_many :recipes
  has_many :ingredients,
    through: :recipes
end

class Ingredient < ActiveRecord::Base
  has_many :recipes
  has_many :foods,
    through: :recipes
end

class Recipe < ActiveRecord::Base
  belongs_to :food
  belongs_to :ingredient
end

This way, you can store additional info inside Recipe

Upvotes: 2

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