This document contains a set of sample questions about "Normalisation" which can be used as a
preparation for the midterm test. The format/coverage/complexity of this sample question is very similar to
the question you will have in the final exam. Hope this helps for you to prepare for the exam.
-------------------------------------------------------------------------------------------------------------------------------
Self-Review Questions ( II)
Use the table (sample daily records for Cafeteria Menu Order) shown below to answer the following
questions (Q1~Q4)
Attribute Name
OrderID
StartTime
NumberInParty
DishNumber
DishName
DishPrice
Quantity
TableID
TableCapacity(Seats)
WaiterID
WaiterName
Sample
Value
99124
1830
3
Sample
Value
99124
1830
3
Sample
Value
99125
1900
6
Sample
Value
99125
1900
6
Sample
Value
99126
1905
2
Sample
Value
99127
2030
4
31
Grilled
Salmon
$23.95
2
1
4
1005
Sasha
33
32
Smoked
Trout
$25.95
3
2
8
1006
Julie
33
Crab
Salad
$26.50
2
2
8
1006
Julie
32
Smoked
Trout
$25.95
2
3
4
1005
Sasha
31
Grilled
Salmon
$23.95
3
1
4
1006
Julie
Crab Salad
$26.50
1
1
4
1005
Sasha
[Q1]
Draw the dependency diagram of the relation presented in the table above. Identify the primary key(s),
draw all dependencies and label them properly (e.g. partial, transitive).
Answer:
Order Start
Time
ID
Number
InParty
Dish
Number
Dish
Name
Dish
Price
Quantity
P
Table
ID
Table
Capacity
T
Waiter
ID
Waiter
Name
T
P
[Q2]
What normal form is the relation currently in? State the reasons for your answer.
No answer is provided, so that you can find your own answer by studying.
1
[Q3]
Normalize the table to third normal form (3NF) and draw the dependency diagrams of the 3NF tables.
Answer:
<Table>
TableID
TableCapacity
< Order>
OrderID
TableID
WaiterID
StartTime
NumberInParty
<Waiter>
WaiterID
WaiterName
<Menu>
DishNumber
DishName
Price
<Order-Line>
OrderID
DishNumber
Quantity
[Q4]
Using the results in Q1.3, draw an entity relationship diagram (ERD). You need to use Crow’s foot
notation. Your diagram should show all relevant attributes including primary and foreign keys.
Indicate all connectivities, cardinalities and optionalities. List all assumptions you made for deciding
optionality which is not clearly specified by the sample table provided.
Answer:
2
3