HackerRank SQL

Type of Triangle

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 3 sides of equal length.
• Isosceles: It’s a triangle with 2 sides of equal length.
• Scalene: It’s a triangle with 3 sides 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

Solution(My SQL):

select case when A+B > C and A+C > B and B+C > A then
            -- is a triangle
            case when A = B and B = C and A = C then 'Equilateral'
                 when A = B or B = C or A = C then 'Isosceles'
                 else 'Scalene'
                 end
            -- is not a triangle
        else 'Not A Triangle' end
from TRIANGLES
;

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