如何使用LinQ To Entities联合两组检索的数据 [英] How to joint two set of retrieved data using LinQ To Entities

问题描述

我使用dbcontext代码首先获得以下类中的这个条件的查询：

Creator！= null& &安培; ArticleAttached！= null&& ！IsCancelled

问题：

如何从类中获取数据表格），并显示

文章标题，赞成数量，评论数量，总计分配，总回应

  A）我使用dbcontext如下：
 
 var ListArticles = dbcontext.LearningActivites 
 .Where（la => ; la.Creator！= null&& la.ArticleAttached！= null&！la.IsCancelled）
 .Select（la => 
 new 
 {
 Id = la.Id，
 Title = la.ArticleAttached.ArticleTitle，
 CreatedWhen = la.ArticleAttached.CreatedAt，
 TTLComment = la.ArticleAttached.Comments.Count，
 TTLOfLikes = la.ArticleAttached.StudentsLiked.Count + la.ArticleAttached.TeachersLiked.Count 
 
}）; 
 
这将得到：
 
文章标题，合计总数，总评论
  

B）如何获得：总分配和总体回答基于以下类别？

 $ $ c $ var var = IsCancelled）
 .Sum（la => la.ClassesAssigned.SelectMany（a => a.LearningActivitiesAssigned.LongCount））; 
  

C）如何联合A + B的结果？ />

显示
文章标题，赞赞数，评论数，总计，总回应

类：

  public class LearningActivity 
 {
 public virtual ArticleCreator Creator {get;组; } 
 public virtual ArticleCreator EditedBy {get;组; } 
 public virtual教师CreatedByTeacher {get;组; 
 public virtual Article ArticleAttached {get;组; 
 public virtual Article ArticleAttachedByOther {get;组; } 
 
 public virtual IList< Class> ClassesAssigned {get;组; } 
 public virtual IList< Group> GroupsAssigned {get;组; } 
 
 public bool IsCancelled {get;组; 
 
 
 
 public class文章
 {
 public string ArticleTitle {get; set;} 
 public virtual IList&&Teacher老师组; } 
 public virtual IList< Student>学生组; } 
 public virtual IList< ArticleComment>评论{get;组; } 
} 
 
 
 public class Student 
 {
 public virtual IList< ArticleCommentStudent>评论{get;组; } 
} 
 
 
 
 public class Class 
 {
 public virtual School School {get;组; } 
 public virtual IList< Student>学生{get;组; } 
 public virtual IList< LearningActivity> LearningActivitiesAssigned {get;组; } 
 
} 
 
 public class Group 
 {
 public virtual School School {get;组; } 
 public virtual IList< Student>学生{get;组; } 
 public virtual ApplicationUser Creator {get;组; 
 
} 
  

谢谢

解决方案

你可以使用这个来分配分配的$ /

TotalAssigned = la.ClassesAssigned。 Sum（x => x.LearningActivitiesAssigned.LongCount）

和 .GroupBy（la => ArticleAttached.ArticleTitle）

  var ListArticles = dbcontext.LearningActivites 
 .GroupBy（la = > la.ArticleAttached.ArticleTitle）
 .Where（la => la.Creator！= null&& la.ArticleAttached！= null&&！la.IsCancelled）
 .Select （la => 
 new 
 {
 Id = la.Id，
 Title = la.ArticleAttached.ArticleTitle，
 CreatedWhen = la.ArticleAttached.CreatedAt，
 TTLComment = la.ArticleAttached.Comments.Count，
 TTLOfLikes = la.ArticleAttached.StudentsLiked.Count + la.ArticleAttached.TeachersLiked.Count 
 TotalAssigned = la.Class esAssigned.Sum（x => x.LearningActivitiesAssigned.LongCount）
}）; 
  

I am using dbcontext Code first to get a query base on this condition for the Classes (tables) below:

Creator != null && ArticleAttached != null && !IsCancelled

Problem :

How to get data from the classes (tables) and show

Article Title, No. of Likes, No. Of Comments, Total Assigned, TotalResponded

A) I use dbcontext as follows:

  var ListArticles = dbcontext.LearningActivites
   .Where(la => la.Creator != null && la.ArticleAttached != null && !la.IsCancelled)
   .Select(la =>
      new
      {
        Id = la.Id,
        Title = la.ArticleAttached.ArticleTitle,
        CreatedWhen = la.ArticleAttached.CreatedAt,
        TTLComment = la.ArticleAttached.Comments.Count,                
        TTLOfLikes = la.ArticleAttached.StudentsLiked.Count + la.ArticleAttached.TeachersLiked.Count

      });

This will get :

 Article Title, Total of Likes, total Comment 

B) How to get : Total Assigned and Total Responded base on the classes below?

 var TotalAssigned = dbcontext.LearningActivites
 .Where(la => la.Creator != null && la.ArticleAttached != null && !la.IsCancelled) 
 .Sum(la => la.ClassesAssigned.SelectMany(a => a.LearningActivitiesAssigned.LongCount));

C) How to joint the result from A + B ?

to show
Article Title, No. of Likes, No. Of Comments, Total Assigned, TotalResponded

Classes:

 public class LearningActivity
 {
   public virtual ArticleCreator Creator { get; set; }        
   public virtual ArticleCreator EditedBy { get; set; }        
   public virtual Teacher CreatedByTeacher { get; set; }   
   public virtual Article ArticleAttached { get; set; }   
   public virtual Article ArticleAttachedByOther { get; set; } 

   public virtual IList<Class> ClassesAssigned { get; set; }
   public virtual IList<Group> GroupsAssigned { get; set; }

   public bool IsCancelled { get; set; }
 }


 public class Article 
 {
   public string ArticleTitle {get;set;}
   public virtual IList<Teacher> TeachersLiked { get; set; }
   public virtual IList<Student> StudentsLiked { get; set; }
   public virtual IList<ArticleComment> Comments { get; set; }
 }


 public class Student
 {
   public virtual IList<ArticleCommentStudent> Comments { get; set; }
 }



 public class Class 
 {
   public virtual School School { get; set; }
   public virtual IList<Student> Students { get; set; }
   public virtual IList<LearningActivity> LearningActivitiesAssigned { get; set; }

 }

 public class Group
 {
  public virtual School School { get; set; }
  public virtual IList<Student> Students { get; set; }
  public virtual ApplicationUser Creator { get; set; }

}

Thanks

解决方案

Can you use this to sum of Assigned

TotalAssigned = la.ClassesAssigned.Sum(x => x.LearningActivitiesAssigned.LongCount)

and .GroupBy(la => la.ArticleAttached.ArticleTitle)

var ListArticles = dbcontext.LearningActivites
   .GroupBy(la => la.ArticleAttached.ArticleTitle)
   .Where(la => la.Creator != null && la.ArticleAttached != null && !la.IsCancelled)
   .Select(la =>
      new
      {
        Id = la.Id,
        Title = la.ArticleAttached.ArticleTitle,
        CreatedWhen = la.ArticleAttached.CreatedAt,
        TTLComment = la.ArticleAttached.Comments.Count,                
        TTLOfLikes = la.ArticleAttached.StudentsLiked.Count + la.ArticleAttached.TeachersLiked.Count
        TotalAssigned = la.ClassesAssigned.Sum(x => x.LearningActivitiesAssigned.LongCount)
      });

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