Explain the assumptions you made about cardinalities in your answer to problem

 

Consider the following 3NF relations about a sorority or fraternity.

 

MEMBER(member_ID, Name,Address, Dues_Owed)

 

OFFICE(Office_Name, Officer_ID, Term_Start_Date, Budget)

 

EXPENSE(Ledger_Number, Office_Name, Expense_Date, Amt_Owed)

 

PAYMENT(Check_Number, Expense_Ledger_Number, Amt_Paid)

 

RECEIPT(Member_ID, Receipt_Date, Dues_Received)

 

COMMITTEE(Committee_ID, Officer_in_Charge)

 

WORKERS( Committee_ID, Member_ID)

 

 

 

  1. Foreign keys are not indicated in these relations. Decide which attributes are foreign keys and justify this.
  2. Draw an ER diagram for these relations, using your answer to problem 1
  3. Explain the assumptions you made about cardinalities in your answer to problem 2. Can you see why ER diagrams are considered more semantically rich than the relational model