Type of Triangle in MYSQL

Question

Problem statement:

Write a query identifying the type of each record in the TRIANGLES table using its three side lengths. Output one of the followin

Answer 1

SELECT
CASE
    WHEN (A > 0 AND B > 0 AND C > 0 AND (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;

Answer 2

SELECT
CASE
    WHEN (A+B>C AND B+C>A AND A+C>B) THEN
    (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)
    ELSE 'Not A Triangle'
END
FROM TRIANGLES;

Answer 3

this answer is working well in sql * plus but not in hackerrank i dont know why? try this.

declare
 cursor mytriangle is select A,B,C from triangles;
 a triangles.A %type;
 b triangles.B %type;
 c triangles.C %type;
 begin
 open mytriangle;
 if mytriangle%isopen then
 loop
 fetch mytriangle into a,b,c;
 exit when mytriangle %notfound;
 case
 when a+b<=c or b+c<=a or a+c<=b then
 dbms_output.put_line('Not A Triangle');
 when a=b and b=c then
 dbms_output.put_line('Equilateral');
 when a=b or b=c or c=a then
 dbms_output.put_line('Isoceles');
 when a+b>=c and b+c>=a and a+c>=b and a!=b and b!=c and c!=a then
 dbms_output.put_line('Scalene');
 else
 dbms_output.put_line('');
 end case;
 end loop;
 close mytriangle;
 else dbms_output.put_line('cannot open the cursor');
 end if;
end;

Answer 4

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 A=C OR B=C THEN 'Isosceles'
            ELSE 'Scalene'
        END
    ELSE 'Not A Triangle'
END
FROM TRIANGLES 

• Step 1: First we select case to check if given input is a triangle or not

• Step 2: If it is a triangle then check for its type. So first case if all sides are the same, then the triangle type is 'Equilateral', then second case if any two sides are the same then the triangle type is 'Isosceles', otherwise the triangle type is 'Scalene'.

Answer 5

SELECT IF(A+B>C AND A+C>B AND B+C>A, IF(A=B AND B=C, 'Equilateral', IF(A=B OR B=C OR A=C, 'Isosceles', 'Scalene')), 'Not A Triangle') FROM TRIANGLES;

Answer 6

   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 C<>B)or(B=C AND C<>A)or(A=C AND A<>B) then 'Isosceles'
else 'Scalene'
end as triangle_type
from TRIANGLES;

here, it will strictly check for the type of the triangles.