[SQL] HackerRank - Type of Triangle

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

CASE 문 안에 CASE 문 !