Consider this table StudentTable: CollegeName IDCollege Address level StudentNam
ID: 3861426 • Letter: C
Question
Consider this table StudentTable:
CollegeName
IDCollege
Address
level
StudentName
StudentID
cci
1
Dammam
1
N1 LN1
s123123
cci
1
Ryadh
3
N2 LN2
S456456
Business administration
2
Abha
2
N3 LN3
S789789
a. Could you tell where the “one fact-one place” rule is violated in this table?
b. Reverse engineer to get the ER model that this table must represent
c. What is the correct relational model?
CollegeName
IDCollege
Address
level
StudentName
StudentID
cci
1
Dammam
1
N1 LN1
s123123
cci
1
Ryadh
3
N2 LN2
S456456
Business administration
2
Abha
2
N3 LN3
S789789
Explanation / Answer
1. one fact in one place”, it signifies that the attribute of an individual is single and is singly related.
It is violated in College name and college id.
3. Relational model
The relational model (RM) for database management is an approach to managing data and NULL appearing in the result of a LEFT JOIN can mean "no value because there is no matching row in the right-hand operand.