The Blunder in SQL | HackerRank Solution

Hello coders, today we are going to solve The Blunder HackerRank Solution in SQL.

Problem

Samantha was tasked with calculating the average monthly salaries for all employees in the EMPLOYEES table, but did not realize her keyboard’s 0 key was broken until after completing the calculation. She wants your help finding the difference between her miscalculation (using salaries with any zeros removed), and the actual average salary.

Write a query calculating the amount of error (i.e. actual – miscalculated:  average monthly salaries), and round it up to the next integer.

Input Format

The EMPLOYEES table is described as follows:

Column	Type
ID	Integer
Name	String
Salary	Integer

Note: Salary is per month.

Constraints

• 1000 < Salary < 10^5

Sample Input

Id	Name	Salary
1	Kristeen	1420
2	Ashley	2006
3	Julia	2210
4	Maria	3000

Sample Output

2061

Explanation

The table below shows the salaries without zeros as they were entered by Samantha:

Id	Name	Salary
1	Kristeen	142
2	Ashley	26
3	Julia	221
4	Maria	3

Samantha computes an average salary of 98.00. The actual average salary is 2159.00.

The resulting error between the two calculations is 2159.00 – 98.00 = 2061.00. Since it is equal to the integer 2061, it does not get rounded up.

Solution – The Blunder in SQL

MySQL

SELECT CEIL(AVG(Salary)-AVG(REPLACE(Salary,'0','')))
FROM  EMPLOYEES

Disclaimer: The above Problem (The Blunder) is generated by Hacker Rank but the Solution is Provided by CodingBroz. This tutorial is only for Educational and Learning Purpose.