1 Test1 N = {n: n is an integer and n 0} X = {x: x = n + 5, where n N} Y = {y: y = 7 * n - 1,...
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Transcript of 1 Test1 N = {n: n is an integer and n 0} X = {x: x = n + 5, where n N} Y = {y: y = 7 * n - 1,...
1
Test1
N = {n: n is an integer and n 0}
X = {x: x = n + 5, where n N}
Y = {y: y = 7 * n - 1, where n N}
List the three smallest elements of each set.
N X Y
0 5 -1
1 6 6
2 7 13
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Test1
N = {n: n is an integer and n 0}
X = {x: x = n + 5, where n N}
Y = {y: y = 7 * n - 1, where n N}
Give the formula of a mapping between X and Y.
The formula cannot contain n.
x = n + 5
n = x – 5
y = 7 * n – 1
= 7 * (x – 5) – 1
= 7x - 36
3
Test1DrivingClass (ClientNo, ClientName, InstructorNo, InstructorName, ClassDate,
ClassTime, CarID)
Which of the following are correct functional dependencies?
CarNo, ClassDate InstructorNo
Yes No
InstructorNo, ClassDate, ClassTime CarNo
Yes No
InstructorName InstructorNo
Yes No
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Test1DrivingClass (ClientNo, ClientName, InstructorNo, InstructorName, ClassDate,
ClassTime, CarID)
Which of the following is a candidate key?
CarNo, ClassDate, ClassTime
Yes No
InstructorNo, ClientNo, ClassDate
Yes No
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Test1
Branch (Bno, Street, City, State, Tel_No, Fax_No)
Staff (Sno, FirstName, LastName, Address, Tel_No, Bno)
Client (ClientNo, Name, StreetAddress, City, State, Gender)
DrivingClass (ClientNo, Sno, ClassDate, ClassTime, CarID)
Car (CarID, Make, Model, Year, Mileage, LastInspectionDate)
List the client information (ClientNo, Name, Gender) with the instructor information (FirstName, LastName)
for all scheduled driving classes for the current date
that use a 2012 Chevrolet Cruze.
The query must produce correct result for any day without modification.
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Test1
Branch (Bno, Street, City, State, Tel_No, Fax_No)
Staff (Sno, FirstName, LastName, Address, Tel_No, Bno)
Client (ClientNo, Name, StreetAddress, City, State, Gender)
DrivingClass (ClientNo, Sno, ClassDate, ClassTime, CarID)
Car (CarID, Make, Model, Year, Mileage, LastInspectionDate)
(Client.ClientNo,Name,Gender,FirstName,LastName)
(ClassDate = CurrentDate() and Make = ‘Chevrolet’ and Model = ‘Cruze’ and Year = 2012)
(Client (Staff (DrivingClass Car)))
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Test1
Branch (Bno, Street, City, State, Tel_No, Fax_No)
Staff (Sno, FirstName, LastName, Address, Tel_No, Bno)
Client (ClientNo, Name, StreetAddress, City, State, Gender)
DrivingClass (ClientNo, Sno, ClassDate, ClassTime, CarID)
Car (CarID, Make, Model, Year, Mileage, LastInspectionDate)
(Client.ClientNo,Name,Gender,FirstName,LastName)
(ClassDate = CurrentDate() and Make = ‘Chevrolet’ and Model = ‘Cruze’ and Year = 2012)
(Client Staff DrivingClass Car)
Cannot Join Client and Staff!
8
Test1Derive table schemas for the following entities with a one-to-many relationship. Use DBDL to specify the table schemas.
E1 E2
A1 B1
A2 B2
A3: composite (A31, A32) B3: composite (B31, B32)
A4 multi-value
PK: (A1, A2) PK: B1
AK: None AK: None
E1 (0..1) ----- IsRelatedTo ----- E2 (1..*)
Attribute: C1, C2
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E1(A1,A2,A31,A32,A4)
PK: A1,A2
AK: NONE
FK: NONE
E2(B1,B2,A1,A2,C1,C2)
PK: B1
AK: NONE
FK: A1,A2 references E1
E2(NewID,B1,B31, B32)
PK: NewID
AK: NONE
FK: B1 references E2
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Decompose the following relation into 3NF. Assume it is in 1NF.
P (A, B, C, D, E, F)
PK A, B, C
AK: NONE
FK: NONE
Functional Dependencies:
A, B, C All
A E
D F
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P2(A,E)
PK: A
AK: NONE
FK: NONE
FDs:
A E
P3(D,F)
PK: D
AK: NONE
FK: NONE
FDs:
D F
A E
C80 0
C70 10
D F
9 X
4 Y
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P2(A,E)
PK: A
AK: NONE
FK: NONE
FDs:
A E
P3(D,F)
PK: D
AK: NONE
FK: NONE
FDs:
D F
A E
C80 0
C80 0
C80 0
C70 10
D F
9 X
9 X
4 Y
4 Y
No Duplicate Records!
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P (A, B, C, D)
PK A, B, C
AK: NONE
FK: A references P2
D references P3
FDs:
A, B, C All
A B C D
C80 100 10 9
C80 300 20 9
C80 300 10 4
C70 100 20 4
14
Decompose the table into BCNF.
Q (X, Y, Z, U, V, W, Q)
PK: X, Y, Z
AK: U, V, W
Functional Dependencies:
X, Y, Z All
U, V, W All
U, V X
W Q
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Q2(W,Q)
PK: W
AK: NONE
FK: NONE
FDs:
W Q
Q3(U, V, X)
PK: U, V
AK: NONE
FK: NONE
FDs:
U, V X
W Q
N1 2.5
N2 3.2
N3 3.2
U V X
1 0 80
2 2 70
1 1 80
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Q (Y, Z, U, V, W)
PK U, V, W
AK: NONE
FK: W references Q2
(U, V) references Q3
FDs:
U, V, W All
Y Z U V W
M14 100 1 0 N1
M14 100 2 2 N2
M14 200 2 2 N3
M14 300 1 1 N1
M14 400 1 0 N2