GATE | GATE CS 2019 | Question 61
A relational database contains two tables Student and Performance as shown below:
The primary key of the Student table is Roll_no. For the Performance table, the columns Roll_no. and Subject_code together from the primary key. Consider the SQL query given below:
SELECT S.Student_name, sum(P.Marks) FROM Student S, Performance P WHERE P.Marks > 84 GROUP BY S.Student_name;
The number of rows returned by the above SQL query is _________ .
Note: This was Numerical Type question.
(D) None of these.
Explanation: In where condition no condition over Roll_no so query produces all groups.