Here are the relations again: BookAuthor(book, year, author, earnings) BookReference(book, year, referencedBook, referencedYear, times) BookReview(book, year, reviewer, score) BookPublish(book, year, publisher, price, num) Recall that in this database, each book may have one or more authors and each author may make a different amount of money from that book

Here are the relations again: BookAuthor(book, year, author, earnings) BookReference(book, year, referencedBook, referencedYear, times) BookReview(book, year, reviewer, score) BookPublish(book, year, publisher, price, num)

Recall that in this database, each book may have one or more authors and each author may make a different amount of money from that book. One book may make reference to other books. One book may be reviewed by different reviewers and get different scores. An author could also be a reviewer and a publisher. Books with the same name but published in different years are considered different books.

Part 1: Write the following triggers in either SQL standard notation or in the Oracle trigger language (tell which notation you chose!) The database should reject insertions into BookAuthor which makes an author earn more than twice as much as a co-author of the same book.