Which tuple relational calculus expresses the following?
List the staff names who manage properties for rent in London.

Question

Which tuple relational calculus expresses the following? 
 List the staff names who manage properties for rent in London.

Accepted Answer

{S.fName, S.lName  | Staff(S) ˄ (∃P) (PropertyForRent(P) ˄  (P.staffNo = S.staffNo) ˄ P.city = ‘London’)}

Answer

{S | Staff(S) ˄ (∃P) (PropertyForRent(P) ˄  (P.staffNo = S.staffNo) ˄ P.city = ‘London’)}

Answer

{S | Staff(S) ˅ (∃P) (PropertyForRent(P) ˅  (P.staffNo = S.staffNo) ˅ P.city = ‘London’)}

Answer

{S.fName, S.lName  | Staff(S) ˅ (∃P) (PropertyForRent(P) ˅  (P.staffNo = S.staffNo) ˅ P.city = ‘London’)}

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