如何使用LINQ按使用SQL“when”子句构造的值排序

Question

这是示例，不要告诉我要规范化。 在许多情况下，这已经标准化了

这是示例查询

select lastname,firstname,gradelevel,major
    case gradelevel
    when 'Freshmen' then 1
    when 'Sophmore' then 2
    when 'Junior' then 3
    when 'Senior' then 4
    else 6
    end as gradelevelrank
    from student
order by gradelevelrank

我如何在 linq 中？

Answer 1

像这样的东西...

var list = (from s in student
select new 
{
   lastname,
   firstname,
   gradelevel,
   major,
   gradeLevelRank =
   (
       gradelevel == "Freshmen" ? 1 : 
       gradelevel == "Sophmore" ? 2 :
       gradelevel == "Junior" ? 3 :
       gradelevel == "Senior" ? 4 : 6
   )
})
.OrderBy(gl => gl.gradeLevelRank)
.ToList();