Consider the following two tables and four queries in SQL.
Book (isbn, bname), Stock(isbn, copies)
Query 1:
SELECT B.isbn, S.copies FROM Book B INNER JOIN Stock S ON B.isbn=S.isbn;
Query 2:
SELECT B.isbn, S.copies FROM Book B LEFT OUTER JOIN Stock S ON B.isbn=S.isbn;
Query 3:
SELECT B.isbn, S,copies FROM Book B RIGHT OUTER JOIN Stock S ON B.isbn=S.isbn
Query 4:
SELECT B.isbn, S.copies FROM Book B FULL OUTER JOIN Stock S ON B.isbn=S.isbn
Which one of the queries above is certain to have an output that is a superset of the outputs of the other three queries?
- Query 1
- Query 2
- Query 3
- Query 4