Explore topic-wise MCQs in Database.

This section includes 8 Mcqs, each offering curated multiple-choice questions to sharpen your Database knowledge and support exam preparation. Choose a topic below to get started.

1.

IDENTIFY_THE_STATEMENT.?$

A. Insert into employee values (1005,Rach,0);
B. Insert into employee values (1002,Joey,335);
C. Insert into employee values (1007,Ross, );
D. None of the mentioned
Answer» B. Insert into employee values (1002,Joey,335);
Discussion
2.

The_primary_key_must_be$

A. Unique
B. Not null
C. Both Unique and Not null
D. Either Unique or Not null
Answer» E.
Discussion
3.

Using the ______ clause retains only one copy of such identical tuples.

A. Null
B. Unique
C. Not null
D. Distinct
Answer» D. Distinct
Discussion
4.

In an employee table to include the attributes whose value always have some value which of the following constraint must be used?

A. Null
B. Not null
C. Unique
D. Distinct
Answer» E.
Discussion
5.

Tuples with null value

A. Tuples with no null values
B. Tuples with any salary
C. All of the mentioned
Answer» C. All of the mentioned
Discussion
6.

The predicate in a where clause can involve Boolean operations such as and. The result of true and unknown is_______ false and unknown is _____ while unknown and unknown is _____

A. Unknown, unknown, false
B. True, false, unknown
C. True, unknown, unknown
D. Unknown, false, unknown
Answer» E.
Discussion
7.

If the attribute phone number is included in the relation all the values need not be entered into the phone number column. This type of entry is given as

A. 0
B. –
C. Null
D. Empty space
Answer» D. Empty space
Discussion
8.

A _____ indicates an absent value that may exist but be unknown or that may not exist at all.

A. Empty tuple
B. New value
C. Null value
D. Old value
Answer» D. Old value
Discussion