Given the information below, create the fully labeled Crow's Foot ERD using a specialization hierarchy where appropriate (use Visio). The ERD must contain all primary keys, foreign keys, and main attributes. Business rules are defined as follows: 1. A small company wants to keep track of the products it sells - children books and toys.
2. All products have common characteristics - the code, the name, the price, and the quantity on hand - as well as unique attributes. The list of such attributes includes but is not limited to the following: the difficulty level (books) and the appropriate age (toys).
3. Customers can purchase a book (hardcover or paperback) or its' electronic version. For regular books, the company wants to record the number of pages per book. For electronic books, the format and the size of the file must be recorded. Some books are available in one format only.