Calculation of table data and sorting in C#

Nozibulla Bashar

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...

5 Replies

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Deepak Saini11y ago
Accepted answer
use this query,

select sum(number) TotalNo,s.studentname,s.studentid from student s inner join result r on s.studentid=r.studentid group by s.studentid,s.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 Bashar11y ago
Thanks a lot sir you Made my day :)sourabh saini
11y ago
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 Bashar11y ago
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 Kumar11y ago
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

Regards,Abhishek