Database Reference
In-Depth Information
ServiceRequest
(continued)
26
Service
Slip
Category Description
Status
Est
Spent Next
ID
ID
Num
Hours Hours
ServiceDate
12
4
8
Both speed and depth
Technician has
2
0
7/16/2013
readings on data unit
scheduled appointment
are signiicantly less than
with owner to attempt
the owner thinks they
to verify the problem.
should be.
13
8
2
Customer describes
Technician suspects
5
2
7/12/2013
engine as making a
problem with either
“clattering” sound.
propeller or shaft and
has scheduled the boat to
be pulled from the water
for further investigation.
14
7
5
Owner accident caused
Technician has scheduled
6
0
7/13/2013
damage to forward
repair.
portion of port side.
15
11
7
Canvas leaks around
Overlap has been created.
8
3
7/17/2013
zippers in heavy rain.
Installation has been
Install overlap around
scheduled.
zippers to prevent leaks.
FIGURE 1-24
Sample data about service requests for Alexamara Marina Group (continued)
Q&A
Question: To check your understanding of the relationship between service requests and boats, answer the
following questions: What is the name of the boat that had a fuse blown on its port motor, and who owns this
boat? What service has been performed on the boat named Gypsy?
Answer: Anderson III, owned by Bill Anderson, had a fuse blown on its port motor. To determine which boat
had a fuse blown on its port motor, first examine the service descriptions in the ServiceRequest table (see
Figure 1-24) to find the slip ID of the boat (5). Next, look for the row in the MarinaSlip table (see Figure 1-22)
in which the slip ID is 5. Anderson III is the boat name in that row, and AN75 is the owner number for that
boat. Finally, to identify the owner, Bill Anderson, look for the row in the Owner table (see Figure 1-21) in
which the owner number is AN75.
The Gypsy had services for an oil change and routine maintenance and for an inspection of the speed
and depth readings on its data unit. To find the service request for the Gypsy, look up the slip ID for the
Gypsy in the MarinaSlip table and find that it is 4. Then look for all rows in the ServiceRequest table for
which the slip ID is 4. There are two such rows. The corresponding service IDs are 3 for an oil change and
routine maintenance and 12 for an inspection of the data unit.
