Keys
Which of the following is the way of specifying uniqueness?
a) relationship
b) key
c) attributes
d) none of these
How many types of keys in database?
a) five
b) six
c) seven
d) eight
Explanation: primary key, candidate key, foreign key, composite primary key, super key, secondary key, alternate key
A set of one or more columns whom combined values are unique among all occurrences is called……
a) primary key
b) candidate key
c) foreign key
d) composite key
Which of the following are properties of candidate key?
a) contain unique values
b) not contain null value
c) contain minimum number of fields
d) all of these
A field or combination of fields used to identify particular row in a relation is called…..
a) primary key
b) candidate key
c) foreign key
d) composite key
