HackerRank-AdvancedSelect-Type of Triangle - case when

Type of Triangle - case when

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 3sides of equal length.
• Isosceles: It’s a triangle with 2sides of equal length.
• Scalene: It’s a triangle with 3sides of differing lengths.
• Not A Triangle: The given values of A, B, and C don’t form a triangle.

Input Format

The TRIANGLES table is described as follows:

Each row in the table denotes the lengths of each of a triangle’s three sides.

Sample Input

Sample Output

Isosceles
Equilateral
Scalene
Not A Triangle

SELECT CASE WHEN A+B <= C OR B+C <= A OR A+C <= B THEN 'Not A Triangle'
            WHEN A=B AND B=C THEN 'Equilateral'
            WHEN (A=B AND A!=C) OR (B=C AND B!=A) OR (A=C AND A!=B)THEN 'Isosceles'
            WHEN A!=B AND B!=C AND A!=C THEN 'Scalene'
            END
FROM TRIANGLES;