Exercise 2 - Solution
Q1
Q2
!
Q3
Q4
(It’s possible to have duplicate author names)
Q5
Q6
Q7
!
Q8
π{name,subj}(σ(mark>70)(STUDENT ⋈(sid=stude) MARK ))
A← π{authorID}author − π{authorID}book
B ← π{ firstName,lastName}(A ⋈ author)
A← π{authorID}book
B ← π{authorID}authorPub
C← π{ f irstName,lastName}((A − B ) ⋈ author)
Q9
Q10