Consider the following schema: Publisher (name, phone, address), PK: name. Book
ID: 672466 • Letter: C
Question
Consider the following schema:
Publisher (name, phone, address), PK: name.
Book (ISBN, title, year, published_by, previous_edition), PK: ISBN, FK: published_by refs Publisher, previous_edition refs Book.
Author (SSN, first_name, last_name, address, income), PK: SSN.
Write(aSSN, bISBN), PK: (aSSN, bISBN), FK: aSSN refs Author, bISBN refs Book.
Author_Editor(aeSSN, works_for), PK: aeSSN, FK: aeSSN refs Author, works_for refs Publisher.
Give relational algebraic expressions or SQL statements for the following plain English language queries based on the above schema.
6.
1.Smith (10 pts) Provide the ISBN of every book whose publisher is different from the publisher of its previous edition.
Explanation / Answer
select ISBN from Book group by previous_edition;