[HackerRank/SQL] Revising Aggregations - The Blunder

Problem. Revising Aggregations - The Blunder

---

Link.

https://www.hackerrank.com/challenges/the-blunder/problem?isFullScreen=true

Population Density Difference | HackerRank

---

Description.

Samantha was tasked with calculating the average monthly salaries for all employees in the EMPLOYEES table, but did not realize her keyboard's  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.:  average monthly salaries), and round it up to the next integer.

 

 

EMPLOYEES 테이블

---

Key Point. 

SELECT,

 

AVG,

 

REPLACE,

 

CEIL, CEIL()함수는 부동 소수점을 올림해서 반환하는 함수

• ex#1 - SELECT CEIL(0.5); → 1
• ex#2 - SELECT CEIL(0.1); → 1
• ex#3 - SELECT CEIL(-1.3); → -1

---

My Answer. 

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

---

References. 

• CEIL 함수: https://www.habonyphp.com/2019/02/ceil.html

MYSQL - CEIL() 함수