使用where子句交叉连接

问题描述：

在Linq中，我必须仅使用方法创建查询，我有2个表:

In Linq i must create a query with method only, i've got 2 tables :

学生(姓，名，结果)
成绩(最高，最低，姓名)

我必须选择学生(LastName，FirstName)并添加分数(Result > Min && Result < Max).

I must select students (LastName, FirstName) and add to it the grade (Result > Min && Result < Max).

最后我必须拥有:

IEnumerable<T> T => LastName, FirstName, Grade

我尝试这个:

var SAG = dc.Students
            .Where(w => w.Year_Result >= 12)
            .Join(dc.Grades, s => true, g => true, (s, g) => 
                  new { s.LastName, 
                        s.FirstName, 
                        Grade = g.Name
                                 .Where(w => (w.Min < s.Result) 
                                          && (w.Max > s.Result))
                        .FirstOrDefault() }).ToList();

但是根据此请求，我只有2个结果，但我必须有40个结果.

But with this request I've only 2 results but I must have 40 results.

答

这对您有用吗?

var SAG =
    from s in dc.Students
    from g in dc.Grades
    where g.Min < s.Result
    where g.Max > s.Result
    select new
    {
        s.LastName, s.FirstName, Grade = g.Name,
    };

(我怀疑您在某处需要<=或>=.)

(I do suspect you need either <= or >= in there somewhere.)

使用where子句交叉连接

相关推荐