1.1.1 - Conceptual Schema - ER Model
Tables: Customer, DonutOrder, Donut ans: Customer:
PK - CustomerID
Rest are customer related fields
DonutOrder:
FK - CustomerID,
FK - DonutID
Qty, SpecialNotes
Donut:
PK - DonutID
Rest are donut fields
Relationships:
Customer - 1:n Identifying - DonutOrder
DonutOrder - n:1 Identifying - Donut
Why are the relationships in 1.1.1 Identifying? ans: The PK's of Customer and Donut are included in the
composite primary key of DonutOrder.
2.1.1 - Physical Scheme - ER Model
Tables: Customer, DonutOrder, Donut ans: Customer:
PK - CustomerID
Rest are customer related fields
DonutOrder:
PK- DonutOrderID
FK - CustomerID
FK - DonutID
Rest of order related
Donut:
PK - DonutID
Rest are donut related
Relationships:
Customer - 1:n Non-identifying - DonutOrder
DonutOrder - n:1 Non-identifying - Donut
Why are the relationships in 2.1.1 Non-Identifying? ans: The PK in DonutOrder is a unique key that does
not include FK of other tables.