Q35

MCQ2 marks, −0.67

Consider the following relational schema. Students(rollno: integer, sname: string) Courses(courseno: integer, cname: string) Registration(rollno: integer, courseno: integer, percent: real) Which of the following queries are equivalent to this query in English? “Find the distinct names of all students who score more than $90\%$ in the course numbered 107” I, II, III and IV I, II and III only I, II and IV only II, III and IV only

(A)

SELECT DISTINCT S.sname FROM Students as S, Registration as R WHERE R.rollno=S.rollno AND R.courseno=107 AND R.percent >90

(B)

$∏_{sname}(σ_{courseno=107 ∧ percent > 90} (Registration ⋈ Students))$

(C)

$\{T \mid ∃S \in Students, ∃R \in Registration ( S.rollno=R.rollno$ $∧ R.courseno=107 ∧ R.percent>90 ∧T.sname=S.sname) \}$

(D)

$\left\{ \langle S_N\rangle \mid ∃S_R∃R_P (\langle S_R,S_N\rangle ∈Students ∧ \\ \langle S_R,107,R_P\rangle ∈Registration ∧ R_P>90) \right\}$

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