ASP. net mvc + LINQ develop a book sales site (2): OBJECT AND ITS RELATIONSHIP

After extraction of the requirement analysis, we obtain the following objects and relationships.

Object:Directory object, book object, author object, Administrator object, user object, comment object, order object, detailed object.

Link:Directories and books are in many-to-one relationship, and authors and books are in one-to-many relationship (not considering co-author) books and comments are one-to-many relationships, users and comments are one-to-many relationships, users and orders are one-to-many relationships, and orders and detailed orders are one-to-many relationships.