Write an SQL query to show which books (title only) have multiple authors.
Concepts in Designing Database
A database design is the process of data organization based on a database model. The process deals with identifying what data should be stored in a database and how data elements relate to each other.
Entity Relationship Diagram
Complex real-world applications call for large volumes of data. Therefore, it is necessary to build a great database to store data safely and coherently. The ER data model aids in the process of database design. It helps outline the structure of an organization’s database by understanding the real-world interactions of objects related to the data. For example, if a school is tasked to store student information, then analyzing the correlation between the students, subjects, and teachers would help identify how the data needs to be stored.
Consider the following typed relational schema describing books and borrowers in a library:
Book(isbn:integer, title:string, publisher:string, year:integer)
Author(isbn:integer, name:string, rank:integer)
Borrower(bid:integer, name:string, address:string)
Borrowings(isbn:integer, borrower:integer, whenTaken:date, whenReturned:date)
Assume the following:
• dates are represented as a count of the number of days since Jan 1 1990
• there is a system function today that returns today's date
• the relational operators < and > allow you test before and after on dates
• all loans are for a period of 14 days
• the whenReturned field is null until the book is returned
• the rank field specifies whether the author is the first, second, third, ... author
Implement solutions to the following:
Write an SQL query to show which books (title only) have multiple authors.
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