Question

我不知道如何利用Linq和EF来进行这一询问。

Imagine I有三个表A、B和C。

A and B have a many-to-many relationship. B and C have a 1-to-many relationship.

我想从B处获得记录,包括C,但从A s Id中过滤。我很容易从B处得到记录:

var result = Context.A.Where(x => x.Id.Equals(aId)).SelectMany(x => x.B);

但是,当我试图将C包括在内时,我不知道如何这样做:

//This doesn t work    
var result = Context.A.Where(x => x.Id.Equals(aId)).SelectMany(x => x.B.Include("C"));

另外,我用无uck(相当于上述)来尝试:

//Not working
var result = (from a in Context.A.Where(x => x.Id.Equals(aId))
              from b in a.B.Include("C")
              select b);

感谢您的帮助。

Answer 1

www.un.org/Depts/DGACM/index_french.htm 推广方法

这是解决办法:

var result = (from b in Context.B.Include("C")
              where b.A.Any(x => x.A.Equals(aId))
              select b);