Designing an ERD for a pet shop for school that does boarding and grooming. On the ERD we have the pet table with "pet_id" that has a many to many relationship with the color table that has colors and an attribute "color_id". Between them we have a composite table or "junction table" with both pet and color id as Foreign Keys and an artifical petcolor_id field as an Primary Key. Do we need this made up petcolor_id primary key field in there?
Thank you for your response. Yes currently that is how I have the junction table 1 primary key with 2 foreign keys, so this correct? Or do I just need 2 foreign keys that would cross reference each other for pet and color?