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WorksheetsICT502_LECTURE 2 RELATIONAL MODEL
Total questions: 15
Worksheet time: 13mins
Relation is also known as
table
file
attribute
entity
(a) of a relation is the number of attributes it contains.
The maximum number of entities that can be involved in a particular relationship
modality
cardinality
TEACHER (teacherID, teacherName, teacherPhoneNo) is the example of:
Relational schema
Relational database schema
Provide THREE (3) properties of a relation
Minimal superkey with no redundancy
foreign key
primary key
candidate key
alternate key
_________ key is a candidate key that was not chosen to be the primary key
superkey
alternate
foreign key
What is the foreign key for the relational schema below:
BRANCH (branchID, branchName, branchAddress, DeptID)
branchID
branchAddress
branchName
DeptID
Referential Integrity is referring to (a) key.
Could Primary Key have null value?
Yes
No
(a) function cannot be done if there is a match foreign key in child's table.
(a) function cannot be done if there is no match existing primary key in parent's table
the application is prohibited from deleting or modifying a parent key when there exists one or more child keys mapped to it.
RESTRICT
NO ACTION
SET NULL
SET DEFAULT
Tuple is also known as
row
record
file
column
Is this table consist of data redundancy?
Yes
No
