DBMS:SQL

Question

Consider the following ORACLE relations:

One (x, y) = {<2, 5>, <1, 6>, <1, 6>, <1, 6>, <4, 8>, <4, 8>}

Two (x, y) = {<2, 55>, <1, 1>, <4, 4>, <1, 6>, <4, 8>, <4, 8>, <9, 9>, <1, 6>}

Consider the following two SQL queries SQ1 and SQ2 :

SQ1: SELECT * FROM One) EXCEPT (SELECT * FROM Two);

SQ2: SELECT * FROM One EXCEPT ALL (SELECT * FROM Two);

For each of the SQL queries, what is the cardinality (number of rows) of the result obtained when applied to the instances above ?

A – 2 and 2 respectively

B – 2 and 1 respectively

C – 1 and 2 respectively

D – 1 and 1 respectively

Comments

C ??

---

@kumar.dilip C is the correct answer. Can u please explain in detail?

---

There is nothing to explain here. Just follow this link.

https://stackoverflow.com/questions/28432720/trying-to-understand-except-all-in-sql-query