SQL

Which of the following statements are TRUE about an SQL query? P : An SQL query can contain a HAVING clause even if it does not have a GROUP BY clause Q : An SQL query can contain a HAVING clause only if it has a GROUP BY clause R : All attributes used in the GROUP BY clause must appear in the SELECT clause S : Not all attributes used in the GROUP BY clause need to appear in the SELECT clause

Common data for Q.50 and Q.51: Consider the following relations A, B and C: $$\textbf{A}: \begin{array}{|c|c|c|} \hline \textbf{Id} & \textbf{Name} & \textbf{Age} \\ \hline 12 & \text{Arun} & 60 \\ 15 & \text{Shreya} & 24 \\ 99 & \text{Rohit} & 11 \\ \hline \end{array} \qquad \textbf{B}: \begin{array}{|c|c|c|} \hline \textbf{Id} & \textbf{Name} & \textbf{Age} \\ \hline 15 & \text{Shreya} & 24 \\ 25 & \text{Hari} & 40 \\ 98 & \text{Rohit} & 20 \\ 99 & \text{Rohit} & 11 \\ \hline \end{array} \qquad \textbf{C}: \begin{array}{|c|c|c|} \hline \textbf{Id} & \textbf{Phone} & \textbf{Area} \\ \hline 10 & 2200 & 02 \\ 99 & 2100 & 01 \\ \hline \end{array}$$ How many tuples does the result of the following SQL query contain?

SELECT A.Id
FROM A
WHERE A.Age > ALL (SELECT B.Age
                   FROM B
                   WHERE B.Name = 'Arun')