sql 查询三条边是否能构成三角形

列表：A B C 代表三角形三条边

输出：

Isosceles
Equilateral
Scalene
Not A Triangle



代码如下：

select CASE
when (A + B) <= C then 'Not A Triangle'
when A = B and B = C then 'Equilateral'
when (A = B) or (B = C) or (A = C) then 'Isosceles'
when A != B and B != C and A != C then 'Scalene'
end from TRIANGLES