I am using the following DB Schema
create table Recipe (id INT NOT NULL PRIMARY KEY AUTO_INCREMENT,
name VARCHAR(25),
description VARCHAR(50),
instructions VARCHAR(500))
ENGINE=InnoDB DEFAULT CHARSET=utf8;
create table Ingredient (id INT NOT NULL PRIMARY KEY AUTO_INCREMENT,
name VARCHAR(50))
create table Measure (id INT NOT NULL PRIMARY KEY AUTO_INCREMENT,
name VARCHAR(30))
create table RecipeIngredient (recipe_id INT NOT NULL,
ingredient_id INT NOT NULL,
measure_id INT,
amount INT,
CONSTRAINT fk_recipe FOREIGN KEY(recipe_id) REFERENCES Recipe(id),
CONSTRAINT fk_ingredient FOREIGN KEY(ingredient_id) REFERENCES Ingredient(id),
CONSTRAINT fk_measure FOREIGN KEY(measure_id) REFERENCES Measure(id))
and using something like this to add data/query it
INSERT INTO Measure (name) VALUES('CUP'), ('TEASPOON'), ('TABLESPOON');
INSERT INTO Ingredient (name) VALUES('egg'), ('salt'), ('sugar'), ('chocolate'), ('vanilla extract'), ('flour');
INSERT INTO Recipe (name, description, instructions) VALUES('Chocolate Cake', 'Yummy cake', 'Add eggs, flour, chocolate to pan. Bake at 350 for 1 hour');
INSERT INTO RecipeIngredient (recipe_id, ingredient_id, measure_id, amount) VALUES (1, 1, NULL, 3);
INSERT INTO RecipeIngredient (recipe_id, ingredient_id, measure_id, amount) VALUES (1, 2, 2, 1);
INSERT INTO RecipeIngredient (recipe_id, ingredient_id, measure_id, amount) VALUES (1, 3, 1, 2);
INSERT INTO RecipeIngredient (recipe_id, ingredient_id, measure_id, amount) VALUES (1, 4, 1, 1);
SELECT r.name AS 'Recipe',
ri.amount AS 'Amount',
mu.name AS 'Unit',
i.name AS 'Ingredient'
FROM Recipe r
JOIN RecipeIngredient ri on r.id = ri.recipe_id
JOIN Ingredient i on i.id = ri.ingredient_id
LEFT OUTER JOIN Measure mu on mu.id = measure_id;
which returns
Recipe | Amount | Unit | ingredient
Chocolate Cake | 3 |null | egg
Chocolate Cake | 1 |TEASPOON | salt
Chocolate Cake | 2 |CUP | sugar
Chocolate Cake | 1 |CU | chocolate
How can I return recipes who's ingredients are a subset of a list of ingredients provided?
e.g I should not return Chocolate cake if list (egg, salt, sugar) is provided. However I should return Chocolate cake if (egg, salt, ham, cheese, sugar, sausage, chocolate) is provided.
You can use aggregation and a having
clause:
SELECT r.name recipe
FROM Recipe r
JOIN RecipeIngredient ri on r.id = ri.recipe_id
JOIN Ingredient i on i.id = ri.ingredient_id
GROUP BY r.id, r.name
HAVING MAX(i.name NOT IN ('egg', 'salt', 'sugar')) = 0
You control the elements the the ingredients should be a subset of with the list of values in the right operand to the IN
conditions.