cleared - relation EXPENSE_LEDGER_NUMBER is a foreign key...

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relation. EXPENSE_LEDGER_NUMBER is a foreign key in PAYMENT referencing LEDGER_NUMBER in the EXPENSE relation. MEMBER_ID in both RECEIPT and WORKERS cross references MEMBER_ID in the MEMBER relation. COMMITTEE_ID in WORKERS cross references COMMITTEE_ID in COMMITTEE. It is inferred that a member sometimes has many receipts, but a receipt must have a member. An expense sometimes has multiple payments, but each payment must have an expense. Each office sometimes has multiple expenses, but each expense must have an office. Each office may have a member as an officer in charge, and each member sometimes holds many offices. An office sometimes is responsible for many committees, and each committee must have an office in charge (although that office may not have a member assigned as officer). Committees sometimes have many workers, and each worker sometimes works on many committees. The E-R diagram is more expressive in that it displays explicitly the minimum cardinalities of relationships and shows exactly which entities are related. A suggested E-R diagram is provided below. Microsoft Visio was used to prepare this diagram.

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