Question

For each case below, graphically represent entities and relationships between entities. Include primary keys, foreign keys where appropriate. For each entity add a couple of attributes (fields) and then provide a brief statement explaining why each entity (table) is in 3NF.

An online retailer of coffee beans maintains a long list of unique coffee flavors. The company purchases beans from a number of suppliers; however, each specific flavor of coffee is purchased from only a single supplier. Many of the customers are repeat purchasers and typically order at least five flavors of beans in each order.

Answer 1

Conference speaker :-

1. Speaker -name
2. Speaker- id
3. Session -time

Registration :-

1. Speaker -name
2. Speaker- id
3. Session -time
4. Attendees-id
5. Attendees- name

Conference session :-

1. Session -time
2. Speaker- id

Conference attendees  :-

1. Attendees-id
2. Attendees- name
3. Session -time

Online retailer of coffee beans maintains :-

1. Coffee- coffee flavors
2. Company- name
3. Company-id
4. Attendees-id
5. Supplier-id

Registration details three represent 3NF.

• Conference speaker
• Conference session
• Conference-attendees
  

Retailer coffee <------many to many----------->Conference-attendees

take multiple coffee and one coffee can multiple take people.// Relationship between many to many.

Conference session<----------many to many------------>Conference-attendees

many people can attend many Conference.// Relationship between many to many.

Conference speaker<-----------one to many------------>Conference session

one speaker can take multiple session // Relationship between one to many.