GATE 2022
Consider the relational database with the following four schemas and their respective instances.
Student(sNo, sName, dNo): (S01,James,D01), (S02,Rocky,D01), (S03,Jackson,D02), (S04,Jane,D01), (S05,Milli,D02)
Dept(dNo, dName): (D01,CSE), (D02,EEE)
Course(cNo, cName, dNo): (C11,DS,D01), (C12,OS,D01), (C21,DE,D02), (C22,PT,D02), (C23,CV,D03)
Register(sNo, cNo): (S01,C11), (S01,C12), (S02,C11), (S03,C21), (S03,C22), (S03,C23), (S04,C11), (S04,C12), (S05,C11), (S05,C21)
SQL Query:
SELECT * FROM Student AS S WHERE NOT EXISTS
(SELECT cNo FROM Course WHERE dNo = 'D01'
EXCEPT
SELECT cNo FROM Register WHERE sNo = S.sNo)
The number of rows returned by the above SQL query is___________.