To Refer three tables for writing queries👇
https://t.me/etl_sql_interview/8

To Refer questions for writing queries👇
https://t.me/etl_sql_interview/37

Answers :

31. SELECT SYSDATE FROM DUAL;

32. SELECT * FROM (SELECT * FROM Worker ORDER BY Salary DESC)
WHERE ROWNUM <= 10;

33. SELECT Salary FROM Worker ORDER BY Salary DESC LIMIT n-1,1;

34. SELECT Salary
FROM Worker W1
WHERE 4 = (
SELECT COUNT( DISTINCT ( W2.Salary ) )
FROM Worker W2
WHERE W2.Salary >= W1.Salary
);

35. Select distinct W.WORKER_ID, W.FIRST_NAME, W.Salary
from Worker W, Worker W1
where W.Salary = W1.Salary
and W.WORKER_ID != W1.WORKER_ID;

Most commonly asked SQL interview questions

https://youtu.be/L-URbfgxBMQ

Click below link to Refer three tables here for writing queries 👇

https://t.me/etl_sql_interview/8

Q-36. Write an SQL query to show the second highest salary from a table.

Q-37. Write an SQL query to show one row twice in results from a table.

Q-38. Write an SQL query to fetch intersecting records of two tables.

Q-39. Write an SQL query to fetch the first 50% records from a table.

Q-40. Write an SQL query to fetch the departments that have less than five people in it.

To Refer three tables for writing queries👇
https://t.me/etl_sql_interview/8

To Refer questions for writing queries👇
https://t.me/etl_sql_interview/41

Answers :

36. Select max(Salary) from Worker
where Salary not in (Select max(Salary) from Worker);

37. select FIRST_NAME, DEPARTMENT from worker W where W.DEPARTMENT='HR'
union all
select FIRST_NAME, DEPARTMENT from Worker W1 where W1.DEPARTMENT='HR';

38. (SELECT * FROM Worker)
INTERSECT
(SELECT * FROM WorkerClone);

39.SELECT *
FROM WORKER
WHERE WORKER_ID <= (SELECT count(WORKER_ID)/2 from Worker);

40. SELECT DEPARTMENT, COUNT(WORKER_ID) as 'Number of Workers' FROM Worker GROUP BY DEPARTMENT HAVING COUNT(WORKER_ID) < 5;

Click below link to Refer three tables here for writing queries 👇

https://t.me/etl_sql_interview/8

Q-41. Write an SQL query to show all departments along with the number of people in there.

Q-42. Write an SQL query to show the last record from a table.

Q-43. Write an SQL query to fetch the first row of a table.

Q-44. Write an SQL query to fetch the last five records from a table.

Q-45. Write an SQL query to print the name of employees having the highest salary in each department.

To Refer three tables for writing queries👇
https://t.me/etl_sql_interview/8

To Refer questions for writing queries👇
https://t.me/etl_sql_interview/43


Answers :

41. SELECT DEPARTMENT, COUNT(DEPARTMENT) as 'Number of Workers' FROM Worker GROUP BY DEPARTMENT;

42. Select * from Worker where WORKER_ID = (SELECT max(WORKER_ID) from Worker);

43. Select * from Worker where WORKER_ID = (SELECT min(WORKER_ID) from Worker);

44. SELECT * FROM Worker WHERE WORKER_ID <=5
UNION
SELECT * FROM (SELECT * FROM Worker W order by W.WORKER_ID DESC) AS W1 WHERE W1.WORKER_ID <=5;

45. SELECT t.DEPARTMENT,t.FIRST_NAME,t.Salary from(SELECT max(Salary) as TotalSalary,DEPARTMENT from Worker group by DEPARTMENT) as TempNew
Inner Join Worker t on TempNew.DEPARTMENT=t.DEPARTMENT
and TempNew.TotalSalary=t.Salary;

SQL Interview Questions

Basic Level : https://intellipaat.com/blog/interview-question/sql-interview-questions/#11


Intermediate Level :

https://intellipaat.com/blog/interview-question/sql-interview-questions/#12


Advance Level :

https://intellipaat.com/blog/interview-question/sql-interview-questions/#13

Commonly asked questions - yet many of us fell short to clearly explain in interview

Difference between concepts which looks similar but they aren't ( eg: where vs having, Exists vs In.. etc )

Part 1 :
https://youtu.be/RZc4QSRRk98

Part 2 :
https://youtu.be/s1QkS4PfiFg

Basics of AWS Relational Database

https://youtu.be/vp_uulb5phM