Below is the use case for a Recipes database, which is used by restaurant owners to record recipes and their ingredients.

Information about ingredients used are stored in the database, including the name and price per kilogram of each ingredient. Because some ingredients have the same or similar names, a description of each ingredient is also included.

Information is stored about recipes, including the name of the recipe, the author of the recipe, the time taken to prepare and the method.

The ingredients required for each recipe are also stored, including the quantity of each ingredient used in the recipe. Each recipe may contain many ingredients, and an ingredient is listed only once for each recipe.

How many of each of the following are there in the relational schema

Attributes that cannot be NULL as they participate in a Primary Key: ?

Attributes that are subject to a Referential Integrity Constraint: ?