Convert many table to excel columns

Question

I create web app for article review.

I have table named Article and each Article have some ArticleReview:

Article

ArticleId
ArticleTitle  
NumberOfComment
NumberOfView
...
ICollection<ArticleReview> Reviews   

Admin can add many user (I call them JueryUser) and send article to them for review, I use table named ArticlePoint for adding/removing User's that can review each Article:

ArticlePoint

public int ArticlePointId { get; set; }
public DateTime CreateOn { get; set; }
public string Id { get; set; }      // Id of User that review Article
public ApplicationUser JuryUser { get; set; }
public string UserId { get; set; } // Id of User that write Article
public int ArticleId { get; set; }
public string JuryReview { get; set; }

When Jury user review article he/she gave article some point, this points is based on question's that provided by Admin, this review's are stored in ArticleReview table.

ArticleReview

ArticleReviewId 
ReviewPoint
ArticleId
ReviewerId

As I said in my previous question I want to get excel export from summery of point that gave to articles by each juery.

I use this below code to generate my excel file:

public static class ExcelExportHelper
    {
        public static string ExcelContentType => "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";

        public static DataTable ListToDataTable<T>(List<T> data)
        {
            PropertyDescriptorCollection properties = TypeDescriptor.GetProperties(typeof(T));
            DataTable dataTable = new DataTable();

            for (int i = 0; i < properties.Count; i++)
            {
                PropertyDescriptor property = properties[i];
                dataTable.Columns.Add(property.Name, Nullable.GetUnderlyingType(property.PropertyType) ?? property.PropertyType);
            }

            object[] values = new object[properties.Count];
            foreach (T item in data)
            {
                for (int i = 0; i < values.Length; i++)
                {
                    values[i] = properties[i].GetValue(item);
                }

                dataTable.Rows.Add(values);
            }
            return dataTable;
        }

        public static byte[] ExportExcel(DataTable dataTable, string heading = "", bool showSrNo = false, params string[] columnsToTake)
        {
            byte[] result = null;
            using (ExcelPackage package = new ExcelPackage())
            {
                ExcelWorksheet workSheet = package.Workbook.Worksheets.Add(String.Format("{0} Data", heading));
                workSheet.View.RightToLeft = true;
                int startRowFrom = String.IsNullOrEmpty(heading) ? 1 : 3;

                if (showSrNo)
                {
                    DataColumn dataColumn = dataTable.Columns.Add("#", typeof(int));
                    dataColumn.SetOrdinal(0);
                    int index = 1;
                    foreach (DataRow item in dataTable.Rows)
                    {
                        item[0] = index;
                        index++;
                    }
                }

                // add the content into the Excel file  
                workSheet.Cells["A" + startRowFrom].LoadFromDataTable(dataTable, true);
                // format header - bold, yellow on black  
                using (ExcelRange r = workSheet.Cells[startRowFrom, 1, startRowFrom, dataTable.Columns.Count])
                {
                    r.Style.Font.Color.SetColor(System.Drawing.Color.White);
                    r.Style.Font.Bold = true;
                    r.Style.Fill.PatternType = OfficeOpenXml.Style.ExcelFillStyle.Solid;
                    r.Style.Fill.BackgroundColor.SetColor(System.Drawing.ColorTranslator.FromHtml("#1fb5ad"));
                }

                // format cells - add borders  
                using (ExcelRange r = workSheet.Cells[startRowFrom + 1, 1, startRowFrom + dataTable.Rows.Count, dataTable.Columns.Count])
                {
                    r.Style.Border.Top.Style = ExcelBorderStyle.Thin;
                    r.Style.Border.Bottom.Style = ExcelBorderStyle.Thin;
                    r.Style.Border.Left.Style = ExcelBorderStyle.Thin;
                    r.Style.Border.Right.Style = ExcelBorderStyle.Thin;

                    r.Style.Border.Top.Color.SetColor(System.Drawing.Color.Black);
                    r.Style.Border.Bottom.Color.SetColor(System.Drawing.Color.Black);
                    r.Style.Border.Left.Color.SetColor(System.Drawing.Color.Black);
                    r.Style.Border.Right.Color.SetColor(System.Drawing.Color.Black);
                }

                if (!String.IsNullOrEmpty(heading))
                {
                    workSheet.Cells["A1"].Value = heading;
                    workSheet.Cells["A1"].Style.Font.Size = 20;

                    workSheet.InsertColumn(1, 1);
                    workSheet.InsertRow(1, 1);
                    workSheet.Column(1).Width = 5;
                }

                result = package.GetAsByteArray();
            }

            return result;
        }

        public static byte[] ExportExcel<T>(List<T> data, string Heading = "", bool showSlno = false, params string[] ColumnsToTake)
        {
            return ExportExcel(ListToDataTable<T>(data), Heading, showSlno, ColumnsToTake);
        }
    }

and use this code in my action method:

  public ActionResult ExportToExcel()
        {
            byte[] filecontent;
            try
            {

                var juryLists = from user in db.Users
                                where user.Roles.Any(r => r.RoleId == "IdOfRole")
                                select user;

                var articles = db.Articles.Include(r=>r.ArticleReview).Where(r2=>r2.ArticleReviews.Any()).ToList();

                List<string> cmnList = new List<string>();
                cmnList.Add("Article Title");
                cmnList.Add("Point Avarage");
                var juryListNames = juryLists.OrderBy(x=>x.Id).Select(x => "JuryPoints : " + x.FullName).ToList();
                cmnList.AddRange(juryListNames);
                string[] columns = cmnList.ToArray();

                var heading = $"Results";

                var dt = new DataTable();
                foreach (var column in columns)
                {
                    dt.Columns.Add(column, typeof(string));
                }

                foreach (var item in articles)
                {
                    var _obj = new object[] { item.ArticleTitle, item.ArticleReviews.OrderBy(x=>x.JuryUserId).Select(x=>x.ArticlePoint).Average() }.Concat(
                        item.ArticleReviews.OrderBy(x => x.JuryUserId).GroupBy(x => x.JuryUserId).Select(x => x.Average(y => y.ReviewPoint))
                            .Cast<object>()).ToArray();
                    dt.Rows.Add(_obj);
                }
                filecontent = ExcelExportHelper.ExportExcel(dt, heading, true, columns);
            }
            catch (Exception e)
            {
                return RedirectToAction("Details",new {id= id });
            }


            return File(filecontent, ExcelExportHelper.ExcelContentType, "Results.xlsx");
        }

My Problem:
I create header for my excel but problem is some jury user wont gave point to article yet and when I generate excel, point of another jury placed in column of another one.
ex: one article sent to 5 jury jury 1,2 and 5 give point to article but after export point of 5th jury place in 3th jury column how can I resolve this?

Answer 1

In order to include those reviews that are not yet added or expected to be filled by the reviewer, you can use a simple left outer join between the jury list and calculated averages for each of the juries who gave reviews. If reviews are missing for a jury, the left outer join will result an empty value average side. Therefore, a simple placeholder like a hyphen,an empty string, or a zero is populated. To achieve all these, you need to change the second for loop in the action method as below:

foreach (var item in articles)
{
    //Prepare list of averages for this article by grouping by individual jury
    //Resulting listcontains objects with two attributes, i.e. JuryUserId and Avg
    //JuryUserId is needed here for later join with user(jury) list
    var averages = item.ArticleReviews.GroupBy(x => x.JuryUserId).Select(x => new { JuryUserId = x.Key, Avg = x.Average(y => y.ReviewPoint) });

    //Left outer join of juries with list of averages  
    //If reviews are not found or yet to be added, a hyphen will be populated as a placeholder 
    var joinedAvg = from jury in juryLists
                join avg in averages on jury.Id equals avg.JuryUserId into j
                from result in j.DefaultIfEmpty()
                orderby jury.Id
                select (result?.Avg.ToString() ?? "-"); //Use any placeholder here

    var _obj = new object[] { item.ArticleTitle, item.ArticleReviews.Select(x => x.ReviewPoint).Average() }.Concat(joinedAvg.Cast<object>()).ToArray();

    dt.Rows.Add(_obj);

}