# Question

Let R = (A, B, C), and let r1 and r2 both be relations on schema R. Give an expression in SQL that is equivalent to each of the following queries.

a. r1 ∪ r2

b. r1 ∩ r2

c. r1 − r2

d. II AB(r1) 1 ΠBC(r2)

a. r1 ∪ r2

b. r1 ∩ r2

c. r1 − r2

d. II AB(r1) 1 ΠBC(r2)

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