PRACTICE • LEARN • GROW

SQL Basics & Queries MCQs

Solve topic-wise placement questions and improve your skills.

SQL Basics & Queries Progress

0 of 30 completed

0% Topic Track

1

What is the primary difference between WHERE and HAVING clauses in SQL?

A. WHERE filters rows before aggregation; HAVING filters groups after aggregation

B. WHERE can only be used with numbers

C. HAVING cannot use aggregate functions

D. They are completely interchangeable

2

Which normal form eliminates partial dependency on candidate keys?

A. First Normal Form (1NF)

B. Second Normal Form (2NF)

C. Third Normal Form (3NF)

D. Boyce-Codd Normal Form (BCNF)

3

Which ACID property ensures that all transaction operations complete or none do?

A. Atomicity

B. Consistency

C. Isolation

D. Durability

4

Why are B+ Trees favored over B-Trees in relational database index storage?

A. All data records are stored in leaf nodes and leaves are linked sequentially for range queries

B. B+ trees require no memory

C. B+ trees do not support balance

D. Leaf nodes store only keys without pointers

5

What happens in a database deadlock condition during two-phase locking?

A. Two transactions mutually wait for locks held by each other indefinitely

B. All locks are released immediately

C. Database crashes permanently

D. Tables get dropped

6

Which SQL constraint or technique is essential for SQL Basics & Queries (Question 6)?

A. PRIMARY KEY and FOREIGN KEY relational integrity

B. Arbitrary table scans

C. Disabling transaction logs

D. Unindexed linear files

7

Which SQL constraint or technique is essential for SQL Basics & Queries (Question 7)?

A. PRIMARY KEY and FOREIGN KEY relational integrity

B. Arbitrary table scans

C. Disabling transaction logs

D. Unindexed linear files

8

Which SQL constraint or technique is essential for SQL Basics & Queries (Question 8)?

A. PRIMARY KEY and FOREIGN KEY relational integrity

B. Arbitrary table scans

C. Disabling transaction logs

D. Unindexed linear files

9

Which SQL constraint or technique is essential for SQL Basics & Queries (Question 9)?

A. PRIMARY KEY and FOREIGN KEY relational integrity

B. Arbitrary table scans

C. Disabling transaction logs

D. Unindexed linear files

10

Which SQL constraint or technique is essential for SQL Basics & Queries (Question 10)?

A. PRIMARY KEY and FOREIGN KEY relational integrity

B. Arbitrary table scans

C. Disabling transaction logs

D. Unindexed linear files

11

Which SQL constraint or technique is essential for SQL Basics & Queries (Question 11)?

A. PRIMARY KEY and FOREIGN KEY relational integrity

B. Arbitrary table scans

C. Disabling transaction logs

D. Unindexed linear files

12

Which SQL constraint or technique is essential for SQL Basics & Queries (Question 12)?

A. PRIMARY KEY and FOREIGN KEY relational integrity

B. Arbitrary table scans

C. Disabling transaction logs

D. Unindexed linear files

13

Which SQL constraint or technique is essential for SQL Basics & Queries (Question 13)?

A. PRIMARY KEY and FOREIGN KEY relational integrity

B. Arbitrary table scans

C. Disabling transaction logs

D. Unindexed linear files

14

Which SQL constraint or technique is essential for SQL Basics & Queries (Question 14)?

A. PRIMARY KEY and FOREIGN KEY relational integrity

B. Arbitrary table scans

C. Disabling transaction logs

D. Unindexed linear files

15

Which SQL constraint or technique is essential for SQL Basics & Queries (Question 15)?

A. PRIMARY KEY and FOREIGN KEY relational integrity

B. Arbitrary table scans

C. Disabling transaction logs

D. Unindexed linear files

16

Which SQL constraint or technique is essential for SQL Basics & Queries (Question 16)?

A. PRIMARY KEY and FOREIGN KEY relational integrity

B. Arbitrary table scans

C. Disabling transaction logs

D. Unindexed linear files

17

Which SQL constraint or technique is essential for SQL Basics & Queries (Question 17)?

A. PRIMARY KEY and FOREIGN KEY relational integrity

B. Arbitrary table scans

C. Disabling transaction logs

D. Unindexed linear files

18

Which SQL constraint or technique is essential for SQL Basics & Queries (Question 18)?

A. PRIMARY KEY and FOREIGN KEY relational integrity

B. Arbitrary table scans

C. Disabling transaction logs

D. Unindexed linear files

19

Which SQL constraint or technique is essential for SQL Basics & Queries (Question 19)?

A. PRIMARY KEY and FOREIGN KEY relational integrity

B. Arbitrary table scans

C. Disabling transaction logs

D. Unindexed linear files

20

Which SQL constraint or technique is essential for SQL Basics & Queries (Question 20)?

A. PRIMARY KEY and FOREIGN KEY relational integrity

B. Arbitrary table scans

C. Disabling transaction logs

D. Unindexed linear files

21

Which SQL constraint or technique is essential for SQL Basics & Queries (Question 21)?

A. PRIMARY KEY and FOREIGN KEY relational integrity

B. Arbitrary table scans

C. Disabling transaction logs

D. Unindexed linear files

22

Which SQL constraint or technique is essential for SQL Basics & Queries (Question 22)?

A. PRIMARY KEY and FOREIGN KEY relational integrity

B. Arbitrary table scans

C. Disabling transaction logs

D. Unindexed linear files

23

Which SQL constraint or technique is essential for SQL Basics & Queries (Question 23)?

A. PRIMARY KEY and FOREIGN KEY relational integrity

B. Arbitrary table scans

C. Disabling transaction logs

D. Unindexed linear files

24

Which SQL constraint or technique is essential for SQL Basics & Queries (Question 24)?

A. PRIMARY KEY and FOREIGN KEY relational integrity

B. Arbitrary table scans

C. Disabling transaction logs

D. Unindexed linear files

25

Which SQL constraint or technique is essential for SQL Basics & Queries (Question 25)?

A. PRIMARY KEY and FOREIGN KEY relational integrity

B. Arbitrary table scans

C. Disabling transaction logs

D. Unindexed linear files

26

Which SQL constraint or technique is essential for SQL Basics & Queries (Question 26)?

A. PRIMARY KEY and FOREIGN KEY relational integrity

B. Arbitrary table scans

C. Disabling transaction logs

D. Unindexed linear files

27

Which SQL constraint or technique is essential for SQL Basics & Queries (Question 27)?

A. PRIMARY KEY and FOREIGN KEY relational integrity

B. Arbitrary table scans

C. Disabling transaction logs

D. Unindexed linear files

28

Which SQL constraint or technique is essential for SQL Basics & Queries (Question 28)?

A. PRIMARY KEY and FOREIGN KEY relational integrity

B. Arbitrary table scans

C. Disabling transaction logs

D. Unindexed linear files

29

Which SQL constraint or technique is essential for SQL Basics & Queries (Question 29)?

A. PRIMARY KEY and FOREIGN KEY relational integrity

B. Arbitrary table scans

C. Disabling transaction logs

D. Unindexed linear files

30

Which SQL constraint or technique is essential for SQL Basics & Queries (Question 30)?

A. PRIMARY KEY and FOREIGN KEY relational integrity

B. Arbitrary table scans

C. Disabling transaction logs

D. Unindexed linear files

Question Palette

Answered

Current

Not Attempted

Wrong