Explore topic-wise MCQs in Structured Query Language (SQL).

This section includes 7 Mcqs, each offering curated multiple-choice questions to sharpen your Structured Query Language (SQL) knowledge and support exam preparation. Choose a topic below to get started.

1.

Which of the following command makes the updates performed by the transaction permanent in the database?

A. ROLLBACK
B. COMMIT
C. TRUNCATE
D. DELETE
Answer» C. TRUNCATE
Discussion
2.

The SQL statement SELECT SUBSTR('abcdefghij', INSTR('123321234', '2', 3, 2), 2) FROM DUAL;prints

A. gh
B. 23
C. bc
D. ab
Answer» B. 23
Discussion
3.

The SQL statementSELECT SUBSTR('123456789', INSTR('abcabcabc', 'b'), 4) FROM DUAL;

A. 6789
B. 2345
C. 1234
D. 456789
Answer» C. 1234
Discussion
4.

What does the following query find?(SELECT DISTINCT r.sidFROM boats b, reserves rWHERE b.bid = r.bidAND b.color = 'red')MINUS(SELECT DISTINCT r.sidFROM boats b, reserves rWHERE b.bid = r.bidAND b.color = 'g

A. Find the sailor IDs of all sailors who have reserved red boats but not green boats
B. Find the sailor IDs of at least one sailor who have reserved red boats but not green boats
C. Find the sailor Ids of atmost one sailor who have reserved red boats but not green boats
D. None of These
Answer» B. Find the sailor IDs of at least one sailor who have reserved red boats but not green boats
Discussion
5.

The SELECT statement SELECT 'Hi' FROM DUAL WHERE NULL = NULL;Outputs

A. Hi
B. FLASE
C. TRUE
D. Nothing
Answer» E.
Discussion
6.

Let the statementSELECT column1 FROM myTable;return 10 rows. The statementSELECT ALL column1 FROM myTable;will return

A. less than 10 rows
B. more than 10 rows
C. exactly 10 rows
D. None of these
Answer» D. None of these
Discussion
7.

Find all the cities with temperature, condition and humidity whose humidity is in the range of 63 to 79

A. SELECT * FROM weather WHERE humidity IN (63 to 79)
B. SELECT * FROM weather WHERE humidity NOT IN (63 AND 79)
C. SELECT * FROM weather WHERE humidity BETWEEN 63 AND 79
D. SELECT * FROM weather WHERE humidity NOT BETWEEN 63 AND 79
Answer» D. SELECT * FROM weather WHERE humidity NOT BETWEEN 63 AND 79
Discussion