我正在尝试解决基于数据库在三种三角形之间进行选择的普通查询

Question

在=之前的语法错误处获取错误

select t_name, 
case 
    when a=b then 'Isoscels' 
    when a=b=c then 'Equilateral'  
    when a<>b<>c then 'Scalene'  
    when (a+b)<c then 'Not A Triangle' 
end as t_name 
from triangles 

Answer 1

我怀疑这是您想要的逻辑：

SELECT
    t_name,
    CASE WHEN a = b THEN 'Isoscels'
         WHEN a = b AND b = c AND a = c THEN 'Equilateral'
         WHEN a <> b AND b <> c AND a <> c THEN 'Scalene'
         ELSE 'Not A Triangle' END AS t_name
FROM triangles;

据我所知，不可能在SQL Server中链接等式表达式，因为您可能可以用其他语言（例如JavaScript或PHP）来做。