SQL Interview Questions and Answers

Basic SQL Interview Questions and Answers

1. What can be used to add a row in a database using SQL?

1. ADD
2. AUGMENT
3. INSERT
4. CREATE

Ans: C

2. What command will you use to remove rows from a table 'AGE'?

1. REMOVE FROM AGE 
2. DROP FROM AGE 
3. DELETE FROM AGE WHERE 
4. UPDATE FROM AGE 

Ans: C

3. What does the SQL WHERE clause do?

1. Limits the column data that are returned
2. Limits the row data that are returned
3. Both a and b
4. None of the above

Ans: B

4. What is the purpose of SQL?

1. To define data structures
2. To specify the syntax of DDL
3. To specify the syntax of DML
4. All of the above

Ans: D

5. The wildcard in a WHERE clause is used when___________

1. A right match is required in a SELECT statement
2. A right match is possible in a CREATE statement
3. A right match is not possible in a SELECT statement
4. None of the above

Ans: C

6. Define a view?

1. A virtual table that can be accessed with SQL commands
2. A base table that can be accessed with SQL commands
3. Both a and b
4. None of the above

Ans: a

7. What command will you use to eliminate a table from a database?

1. ELIMINATE TABLE CUSTOMER;
2. DROP TABLE CUSTOMER;
3. DELETE TABLE CUSTOMER;
4. APPRISE TABLE CUSTOMER;

Ans: b

8. What does an ON UPDATE CASCADE ensure?

1. Standardization
2. Data Integrity
3. Both a and b
4. None of the above

Ans: B

9. What does SQL data definition commands make up?

1. DDL
2. DML
3. DQL
4. DCL

Ans: A

10. Choose the valid SQL for an Index?

1. CREATE INDEX ID;
2. ALTER INDEX ID;
3. ADD INDEX ID;
4. DELETE INDEX ID;

Ans: A

11. Which SQL keyword(s) is used with wildcards?

1. IN and NOT IN
2. NOT IN only
3. LIKE only
4. IN only

Ans: C

12. Choose the correct order of keywords for SQL SELECT statements

1. WHERE, SELECT, FROM
2. SELECT, FROM, WHERE
3. SELECT, WHERE, FROM
4. FROM, WHERE, SELECT

Ans: b

13. What is a subquery in an SQL SELECT statement enclosed in?

1. brackets []
2. braces {}
3. parenthesis () 
4. none of the above

Ans: C

14. What is the result of a SQL SELECT statement?

1. report
2. form
3. table
4. file

Ans: c

15. Select the built-in functions provided by SQL

1. SUM, MIN, MAX, MULT, AVG
2. SUM, MULT, DIV, MIN, AVG
3. SUM, MIN, MAX, NAME, AVG
4. COUNT, SUM, AVG, MAX, MIN

Ans: D

Online Assessments for Assessing Programmers

An online test can be used to measure different types of technical skills. You can make use of an online test platform to administer multiple-choice SQL query interview questions in the pre-hiring stage. If the job role requires an assessment of coding abilities, then you can make use of the online coding tests to analyse simple to complex coding skills. You can assess different levels of coding proficiencies required for job roles

across industries using online assessments. You also have the option to measure specific programming skill sets by using project-based coding questions or customised domain-specific questions. The online tests are automated to ensure a quick turnaround of results.

How Do I Prepare for SQL Interviews

Preparing for SQL interviews requires a combination of theoretical knowledge and practical skills. Here are some tips to help you prepare:

• Review the Basics: Enables performance benchmarking with a real-time feedback mechanism
• Practice Coding: Practice coding SQL queries and statements. Try to solve sample problems, and create queries to retrieve and manipulate data.
• Learn SQL Tools and Platforms: Familiarize yourself with SQL platforms and tools like MySQL, Oracle, and SQL Server. Know how to use their command-line interfaces, web interfaces, and IDEs.
• Understand Database Architecture: Understand the architecture of databases and how to create and manage them.
• Study Advanced Topics: Learn about advanced SQL topics like indexes, constraints, transactions, stored procedures, triggers, and views.