Question

Which of the following SQL statements will display the name of each publisher that publishes a book classified in the COMPUTER category?

a) SELECT publisher_name FROM PUBLISHER WHERE category = 'COMPUTER'
b) SELECT publisher_name FROM PUBLISHER JOIN BOOKS ON PUBLISHER.publisher_id = BOOKS.publisher_id WHERE category = 'COMPUTER'
c) SELECT publisher_name FROM PUBLISHER INNER JOIN BOOKS ON PUBLISHER.publisher_id = BOOKS.publisher_id AND category = 'COMPUTER'
d) SELECT publisher_name FROM PUBLISHER JOIN BOOKS ON PUBLISHER.publisher_id = BOOKS.publisher_id GROUP BY publisher_name HAVING category = 'COMPUTER'

Answer 1

The correct SQL statement to find publishers for books in the COMPUTER category involves an INNER JOIN between the PUBLISHER and BOOKS tables, filtering the category as 'COMPUTER'.

Step-by-step explanation:

The correct SQL statement to display the name of each publisher that publishes a book classified in the COMPUTER category is:

c) SELECT publisher_name FROM PUBLISHER INNER JOIN BOOKS ON PUBLISHER.publisher_id = BOOKS.publisher_id AND BOOKS.category = 'COMPUTER'

This statement uses an INNER JOIN to combine rows from PUBLISHER and BOOKS tables based on the condition that their publisher_id columns match. The WHERE clause filters the joined table to only include rows where the category column in the BOOKS table matches 'COMPUTER'. Therefore, it returns the names of the publishers associated with books in the COMPUTER category.