Note that we may have some 3 entity relationships here. For the 3 entity relatio

Question

Note that we may have some 3 entity relationships here. For the 3 entity relationships, you will need to add a weak entity.

Can you see what is wrong with my ERD:

ReservationNumber CustomerPhone CustomerName CustomerAddress Date Scheduled pickup time ScheduledTime (min) PricePaid ActualTime (min) DriversHourlyRate DriverSalaryEarned PickupLocation DropOffLocation NumberOfPassengers PickupLattitute PickupLongitude DropOffLattitude DropOffLongitude ActualPickupTime Driver TruckLicensePlate TruckColor TruckCapacity EmployeeInPassengerSeat EmployeeInPassengerHourlyRate EmployeeInPassengerSeatSalaryEarned 24333 212-555-2222 Tucker Green house behind the Dairy Queen 10/15/2015 7pm 20 $15 22 $                        34.00 $12.47 Joe's Bar Mary Sue's house 6 38.8522 40.7953 -77.0378 -73.1003 7:04 Joe MyFird Muddy 8 Billy Bob $22 $8.07 323423 718-555-2222 Thurston Howell III Howel Manor 9/23/2015 4pm 10 $10 9 $                        23.00 $                            3.45 Howel Manor Gilligans bar 2 23.23 23.22 34.22 2.33 4:00pm Joe MyFird Muddy 8 Phil, from accounting $12 $1.80 9342343 310-555-1111 Melba Toast Third house down Hawkin's lane 11/20/2015 3pm 30 $14 $                        31.00 $                                -   Mary Sue's house Billy's Wrecking Yard 2 -77.0378 -73.1003 33.33 32.34 Billy Bob Geep Muddy 6 Phil, from accounting $12 $0.00 1001001 800-555-2323 Adam A 2 Galactica Way 1/1/2001 2am 20 $43 34 $                        63.00 $                         35.70 Battlestar Pegasus Galactica 2 34.3 34.3 3.4 3.4 2:14am Boom R IShootCylons Silver 12 Helo $                                                        15.00 $8.50 3434 718-555-2222 Thurston Howell III Howel Manor

Explanation / Answer

Generally weak entity is , dependent on others since it doesn't have a direct primary key.

In your data...Reservation number is weak entity and remaining data can be identifies as... combination of (Reservation number + CustomerPhone) .

******Assuming customer phonenumber is unique****

Related Questions

Navigate

• Browse (All)
• Browse N
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.