02/03/2021
**SQL 21 Interview Questions**
1. Explain the term "Relational" in RDBMS.
2. What is the purpose of "Normalization" in a database management System
3. Describe the two different situations when you will use subquery or join.
4. What is an outer join? What are its types?
5. What is the typical use of EXISTS operator? Give a query example.
6. What are different properties of DISTINCT operator?
7. Explain the rule of precedence between AND & OR Operators? How to override the rule?
8. What is default use of operator || ? How can you change its meaning & hence its use?
9. What the temporal operator is used for in MySQL? Give an example,
10. How do you evaluate a common arithmetic expression like A + B * (C - D) / E. Write the SQL query for MySQL DBMS.
11. Arrange ORDER BY, LIMIT, WHERE clauses in their proper sequence if to be used together in an SQL query.
12. SELECT * FROM emp AS e1 WHERE sal = (SELECT sal FROM emp AS e2 WHERE ename = 'MARTIN' AND e2.deptno = e1.deptno); Rewrite this query to operate at better performance. What this type of query called?
13. Write a query to list rows from 11th to 15th from a table named T.
14. What will be the result of this query - SELECT deptno, MAX(AVG(sal)) FROM emp GROUP BY deptno; in MySQL. Write a query to be used in MySQL to list maximum of the department number wise average salary amount along with the department number to which it belongs.
15. What is Data integrity? How is that implemented in relational databases like MySQL?
16. Why you require to define constraint at table level if it can be defined at column level?
17. Which constraint will you use for implementation of domain integrity?
18. What is the purpose of DEFAULT constraint? Give an example case of its use?
19. What is the difference between WHERE and HAVING clauses?
20. Arrange HAVING, ORDER BY, GROUP BY and WHERE clauses in their proper sequence if they are to be used together in a SELECT statement,
21. What are different ways of creating copy of table without copying the data?
This is not an exhaustive list of questions, there can be many many more you might face in the interview. So you need a comprehensive course to learn all that required to face an interview as a developer. If you really want to be the master in SQL but starting with no prior coding experience, then this course is for you. Updated every week with new lessons, this course is designed & presented by instructor with 23+ years experience in the industry with you in consideration at one end and industry aspirations on the other. It comes with a Q/A forum where you can raise doubts and be assured to get answer within 24 hours. Backed With 30 days 100% money back guarantee you're protected against any loss and assured of the best quality. Enroll now with coupon code to avail heaviest discount MYSQLBOOTCAMP2020MAR
Link :
Instant job ready SQL course with MySQL - Ultimate SQL bootcamp for Data Analysis, Data Science & Web Developers
