1. Add an index for the customer’s last name 2. Add an index on the number of days it took to ship the order. If shipdate is unavailable, use January 1, 2020 for the calculations.
3. There seems to be some confusion in data entry about book titles due to similar titles. For example, Golden Son by Pierce Brown vs. The Golden Son by Shilpi Somaya Gowda. Add a unique constraint for the book title. Can you add a unique constraint to a column containing duplicate data? If you run into problems, please provide queries that allow you to fix the inconsistencies. If you need to update or delete any data in BOOKS feel free to do so! You may need to change one of the book titles (hint: the one by Shilpi Somaya Gowda), use UPDATE. One of the "Database Implementation" records seem to have no link to an author, use DELETE.
Do you think it may be a good idea to replace FK constraint in ORDERI ITEMS to FK with ON DELETE CASCADE option?
4. Make sure that all book records have a title, publisher, cost, and retail, and that all publishers have contact and phone.
5. Add a constraint so that all retail prices have to be between $2 and $200.