title: Lambda Expression for join
body: <pre><code>public class CourseDetail
      {
          public CourseDetail();
          public string CourseId { get; set; }
          public string CourseDescription { get; set; }
          public long CourseSer { get; set; }
      }
  
   public class RefUIDByCourse
      {
          public long CourseSer {  get;  set; }
          public double DeliveredDose{ get; set; }
          public double PlannedDose{ get; set; }
          public string RefUID {  get;  set; }
       }
   public class RefData
      {
         public double DailyDoseLimit {  get;  set; }
         public string RefName {  get;  set; }
         public string RefUID {  get;  set; }
         public double SessionDoseLimit {  get;  set; }
      }
  
  public class CourseSummary  
      {    
            public long CourseSer { get; set; } 
            public double DeliveredDose{ get; set; } 
            public double PlannedDose{ get; set; } 
            Public List&lt;RefData&gt; lstRefData {get;set;} 
      }
  </code></pre>
  
  <p>For one courseSer there can be multiple RefUID in RefUIDByCourse
  and for every RefUID there will be one record in RefData</p>
  
  <p><strong>i have list of CourseDetail,RefUIDByCourse and RefData
  now for the courseser exist in coursedetail i have to create list of CourseSummary.</strong></p>
  
  <p><em>one thing i can do is do for loop for coursedetail and fetch respective refdata using linq query and create a object of coursesummary and add it in list.</em></p>
  
  <p><em><strong>but is there any way to do it by one linq query instead of doing loop through</em></strong></p>