Calculation of table data and sorting in C#

Question

I am new to C# and i am building an application on result management where I have two tables named 'student' and 'result'. The primary key of student table is foreign key of result table. In the result table result of different subject a student is stored using the foreign key to identify whose result is it.Now i want to calculate the total result of every student and sort it. From where i can identify who is first.I can calculate total result of a single student but i cant understand how can i calculate total result of all student at a time. I use the below code for calculating result of a single student:

SqlDataAdapter sda = new SqlDataAdapter("SELECT tblResult.* FROM  tblResult where [Student ID]='" + studentid + "'and Semester='"+"First"+"'", con);

                DataTable dt = new DataTable();

                sda.Fill(dt);

                dgvShowResult.DataSource = dt;

                int sum = 0;

                for (int i = 0; i < dgvShowResult.Rows.Count; i++)

                    sum += Convert.ToInt32(dgvShowResult.Rows[i].Cells[21].Value);

Here dgvShowResult is a dataGridView.First i select all result of a student using its ID and then place it in a dataGridView.So i can easily count total marks.

Can anyone suggest me with my problem please...

Deepak Saini · Answer

use this query select sum(number) TotalNos.studentnames.studentid from student s inner join result r on s.studentid=r.studentid group by s.studentids. studentname order by TotalNo desc if u using the grid view your calculate int total = 0; protected void gvEmp_RowDataBound( object sender GridViewRowEventArgs e) { if (e.Row.RowType== DataControlRowType .DataRow) { total += Convert .ToInt32( DataBinder .Eval(e.Row.DataItem Amount )); } if (e.Row.RowType== DataControlRowType .Footer) { Label lblamount = ( Label )e.Row.FindControl( lblTotal ); lblamount.Text = total.ToString(); } }

Nozibulla Bashar · Answer

Thanks a lot sir you Made my day :) sourabh saini

Kailash Chandra Behera · Answer

Below Code may help you do copy all code and examine DataTable DT1 = new DataTable(); DT1.Columns.Add(ID typeof(int)); DataRow DR = DT1.NewRow(); DR[0] = 1; DT1.Rows.Add(DR); DR = DT1.NewRow(); DR[0] = 2; DT1.Rows.Add(DR); DR = DT1.NewRow(); DR[0] = 3; DT1.Rows.Add(DR); DataTable DT2 = new DataTable(); DT2.Columns.Add(ID typeof(int)); DT2.Columns.Add(RES typeof(int)); DR = DT2.NewRow(); DR[0] = 1; DR[1] = 1; DT2.Rows.Add(DR); DR = DT2.NewRow(); DR[0] = 2; DR[1] = 1; DT2.Rows.Add(DR); DR = DT2.NewRow(); DR[0] = 1; DR[1] = 3; DT2.Rows.Add(DR); DataRow[] DRs = null; foreach (DataRow DR1 in DT1.Rows) { DRs = DT2.Select(ID= + DR1[0]); Console.WriteLine(Result of ID  + DR1[0].ToString() +  Nos  + DRs.Length); } Console.Read(); Kindly mark as answer if it helps you

Nozibulla Bashar · Answer

Sorry Sir i think i can't make you get my problem properly.I want to calculate total marks for every specific student from my 'result' table.But in this article it shows the whole total which i don't need.I think i have to do it using my foreign key which i mentioned above.In the result table for specific studentID i mean the foreign key i have to calculate the total result. Thanks

Abhishek Singh · Answer

Hi  Please follow the beautiful articles below. http://asp.net-informations.com/gridview/gridview-summary.htm http://www.asp.net/web-forms/overview/data-access/custom-formatting/displaying-summary-information-in-the-gridview-s-footer-vb Hope this will help RegardsAbhishek