[HackerRank][SQL(Oracle)] Type of Triangle

 

※  The TRIANGLES table is described as follows:

( Each row in the table denotes the lengths of each of a triangle's three sides. )

 

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■  [Advanced Select]  Type of Triangle

https://www.hackerrank.com/challenges/what-type-of-triangle/problem?isFullScreen=true 

Q.

Write a query identifying the type of each record in the TRIANGLES table using its three side lengths. Output one of the following statements for each record in the table:
    *  Equilateral: It's a triangle with sides of equal length.
    *  Isosceles: It's a triangle with sides of equal length.
    *  Scalene: It's a triangle with sides of differing lengths.
    *  Not A Triangle: The given values of A, B, and C don't form a triangle.

A.

SELECT 
	CASE
		WHEN A+B<=C				THEN 'Not A Triangle'
		WHEN A=B AND B=C AND C=A	THEN 'Equilateral'
		WHEN A=B OR B=C OR C=A	THEN 'Isosceles'
		ELSE							 'Scalene'
	END 
		AS COL
FROM TRIANGLES;