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I'm trying to calculate GPA using Sqlite database but it's only getting one course grade from the database, not all courses

I am trying to build a University system and in this method, I'm trying to calculate GPA using Sqlite database that contains all needed informationthis is the table of the student but it's only getting one course grade from the database, not all courses
public double GpaCal()
{
connect();
SQLiteCommand command = new SQLiteCommand("select count(courseCode) from " + student + " where term = '" + termInfo + "';", myConnection);
command.Connection = myConnection;
int numberOfCourses = 0;
numberOfCourses = Convert.ToInt32(command.ExecuteScalar());
string[] Subject = new string[numberOfCourses];
double[] Marks = new double[numberOfCourses];
double[] credithours = new double[numberOfCourses];
double[] TGPA = new double[numberOfCourses];
command.CommandText = "select * from " + student + " where term = '" + termInfo
+ "';";
SQLiteDataReader reader = command.ExecuteReader();
while(reader.Read())
{
for (int i = 0; i < numberOfCourses; i++)
{
I think the problem is here
Grades = (double)reader.GetDouble("grade");
Marks[i] = Grades;
ECTS = (int)(long)reader.GetDouble("ECTS");
credithours[i] = ECTS;
here is the method to convert the grade into GPA:
if (Marks[i] >= 90 && Marks[i] <= 100)
{
TGPA[i] = 4.00 * credithours[i];
}
else if (Marks[i] >= 85 && Marks[i] <= 89.99)
{
TGPA[i] = 3.50 * credithours[i];
}
else if (Marks[i] >= 80 && Marks[i] <= 84.99)
{
TGPA[i] = 3.00 * credithours[i];
}
else if (Marks[i] >= 75 && Marks[i] <= 79.99)
{
TGPA[i] = 2.50 * credithours[i];
}
else if (Marks[i] >= 70 && Marks[i] <= 74.99)
{
TGPA[i] = 2.00 * credithours[i];
}
else if (Marks[i] >= 65 && Marks[i] <= 69.99)
{
TGPA[i] = 1.50 * credithours[i];
}
else if (Marks[i] >= 60 && Marks[i] <= 64.99)
{
TGPA[i] = 1.00 * credithours[i];
}
else if (Marks[i] >= 50 && Marks[i] <= 59.99)
{
TGPA[i] = 0.50 * credithours[i];
}
else if (Marks[i] > 0.00 && Marks[i] <= 49.99)
{
TGPA[i] = 0.00 * credithours[i];
}
else
{
}
}
double GPA = 0;
double TC = 0;
for (int i = 0; i < numberOfCourses; i++)
{
GPA = GPA + TGPA[i];
TC = TC + credithours[i];
ClassGpa = GPA / TC ;
}
return ClassGpa;
}
return 0.00;
}

Now it's working this is the code:
student in the SQL command is the table of the student who signed in
termInfo is the student's current term or previous term so I can calculate GPA for a specific term
public double GpaCal()
{
connect();
double[] Marks = new double[3];
double[] credithours = new double[3];
double[] TGPA = new double[3];
SQLiteCommand command = new SQLiteCommand ("select grade,ECTS from " + student + " where term = '" + 3 + "';", myConnection);
SQLiteDataReader reader = command.ExecuteReader();
int i = 0;
while (reader.Read())
{
Grades = (double)reader.GetValue(reader.GetOrdinal("grade"));
Marks[i] = Grades;
ECTS = (int)(long)reader.GetValue(reader.GetOrdinal("ECTS"));
credithours[i] = ECTS;
i++;
}
for (int j= 0; j < 3; j++)
{
if (Marks[j] >= 90 && Marks[j] <= 100)
{
TGPA[j] = 4.00 * credithours[j];
}
else if (Marks[j] >= 85 && Marks[j] <= 89.99)
{
TGPA[j] = 3.50 * credithours[j];
}
else if (Marks[j] >= 80 && Marks[j] <= 84.99)
{
TGPA[j] = 3.00 * credithours[j];
}
else if (Marks[j] >= 75 && Marks[j] <= 79.99)
{
TGPA[j] = 2.50 * credithours[j];
}
else if (Marks[j] >= 70 && Marks[j] <= 74.99)
{
TGPA[j] = 2.00 * credithours[j];
}
else if (Marks[j] >= 65 && Marks[j] <= 69.99)
{
TGPA[j] = 1.50 * credithours[j];
}
else if (Marks[j] >= 60 && Marks[j] <= 64.99)
{
TGPA[j] = 1.00 * credithours[j];
}
else if (Marks[j] >= 50 && Marks[j] <= 59.99)
{
TGPA[j] = 0.50 * credithours[j];
}
else if (Marks[j] > 0.00 && Marks[j] <= 49.99)
{
TGPA[j] = 0.00 * credithours[j];
}
else
{
}
}
double GPA = 0;
double TC = 0;
for (int x = 0;x < 3; x++)
{
GPA = GPA + TGPA[x];
TC = TC + credithours[x];
ClassGpa = GPA / TC ;
}
return ClassGpa;
}

Select data from SQL based on specific values using C# perform operations

I need to select data saved on the basis of different ages, design alternatives and experiences in SQL using C#. The operations are performed in the data using for loop and the loop runs for all the IDs with the specified Age, Design alternative and experience. The code is attached.
The results I am getting are the same for every age or design alternatives entered.
public partial class Form3 : Form
{
SqlCommand cnd;
SqlConnection conn = new SqlConnection(#"Data Source=HAIER-PC;Initial Catalog=c_util;Integrated Security=True");
int[] R = new int[10];
double[] W = { 4.11, 2.21, 3.42, 3.01, 2.34, 4.10,3.03, 1.18, 1.99, 5.03 };
double[] S = new double[10];
double sum;
double[] wp1= new double[10];
double[] squ= new double[10];
double[] l = new double[10];
double learn = 0.5;
int op;
int ID;
public Form3()
{
InitializeComponent();
}
private void button8_Click(object sender, EventArgs e)
{
int n;
if (conn.State != ConnectionState.Open)
conn.Open();
cnd = new SqlCommand("select * from CDes where Age='" + comboBox1.Text + "' AND Exper='" + comboBox2.Text + "'AND Design='" + comboBox3.Text + "' ", conn);
SqlDataReader myreader = cnd.ExecuteReader();
int[] R = new int[10];
while (myreader.Read())
{
string id = myreader.GetInt32(0).ToString();
string shell = myreader.GetInt32(4).ToString();
string baseg = myreader.GetInt32(5).ToString();
string vnt = myreader.GetInt32(6).ToString();
string price = myreader.GetInt32(7).ToString();
string impactliner = myreader.GetInt32(8).ToString(); ;
string eyeport = myreader.GetInt32(9).ToString();
string face = myreader.GetInt32(10).ToString();
string comfort = myreader.GetInt32(11).ToString();
string strap = myreader.GetInt32(12).ToString();
string wgt = myreader.GetInt32(13).ToString();
ID = Convert.ToInt32(id);
R[0] = Convert.ToInt32(shell);
R[1] = Convert.ToInt32(baseg);
R[2] = Convert.ToInt32(vnt);
R[3] = Convert.ToInt32(price);
R[4] = Convert.ToInt32(impactliner);
R[5] = Convert.ToInt32(eyeport);
R[6] = Convert.ToInt32(face);
R[7] = Convert.ToInt32(comfort);
R[8] = Convert.ToInt32(strap);
R[9] = Convert.ToInt32(wgt);
}
//Kohonen
for ( n = 0; n <=ID; n++)
{
S[0] = R[0] - W[0];
squ[0] = Math.Pow(S[0], 2);
S[1] = R[1] - W[1];
squ[1] = Math.Pow(S[1], 2);
S[2] = R[2] - W[2];
squ[2] = Math.Pow(S[2], 2);
S[3] = R[3] - W[3];
squ[3] = Math.Pow(S[3], 2);
S[4] = R[4] - W[4];
squ[4] = Math.Pow(S[4], 2);
S[5] = R[5] - W[5];
squ[5] = Math.Pow(S[5], 2);
S[6] = R[6] - W[6];
squ[6] = Math.Pow(S[6], 2);
S[7] = R[7] - W[7];
squ[7] = Math.Pow(S[7], 2);
S[8] = R[8] - W[8];
squ[8] = Math.Pow(S[8], 2);
S[9] = R[9] - W[9];
squ[9] = Math.Pow(S[9], 2);
sum = squ[0] + squ[1] + squ[2] + squ[3] + squ[4] + squ[5] + squ[6] + squ[7] + squ[8] + squ[9];
if (sum >= 75)
{
op = 1;
}
else
{
op = 0;
}
wp1[0] = W[0] + (learn * op * S[0]);
wp1[1] = W[1] + (learn * op * S[1]);
wp1[2] = W[2] + (learn * op * S[2]);
wp1[3] = W[3] + (learn * op * S[3]);
wp1[4] = W[4] + (learn * op * S[4]);
wp1[5] = W[5] + (learn * op * S[5]);
wp1[6] = W[6] + (learn * op * S[6]);
wp1[7] = W[7] + (learn * op * S[7]);
wp1[8] = W[8] + (learn * op * S[8]);
wp1[9] = W[9] + (learn * op * S[9]);
}
myreader.Close();
conn.Close();
textBox13.Text = wp1[0].ToString();
textBox14.Text =wp1[1].ToString();
textBox15.Text = wp1[2].ToString();
textBox20.Text = wp1[3].ToString();
textBox16.Text = wp1[4].ToString();
textBox21.Text = wp1[5].ToString();
textBox17.Text = wp1[6].ToString();
textBox22.Text = wp1[7].ToString();
textBox18.Text = wp1[8].ToString();
textBox23.Text = wp1[9].ToString();
}

I think it is caused by the you do not use the loop internal n variable, so you always read the same data. Also you overwrites R table elements in every while loop iteration.

Merge row dynamically while export using epplus

I want to merge rows in my exported excel using epplus. This code below only works if I just have one same value in one column.
e.g (I merge same value in Col1 row) :
But, if I have another table like this, the code getting error while do merge (I merge same value in Col1 and Col2 row)
Pls, help me fix the code.
void mergeCells(DataTable dt, int startIndex, int totalColumns, ExcelWorksheet ws)
{
if (totalColumns == 0) return;
int i, count = 1;
ArrayList lst = new ArrayList();
lst.Add(ws.Cells[2, 1]);
var ctrl = ws.Cells[startIndex + 1, 1];
for (i = 1; i <= dt.Rows.Count; i++)
{
ExcelRange nextMerge = ws.Cells[i + totalColumns + 1, 1];
if (ctrl.Text == nextMerge.Text)
{
count++;
lst.Add(ws.Cells[i, 1]);
}
else
{
if (count > 1)
{
ws.Cells[i + 1, 1, i + count, 1].Merge = true;
mergeCells(new DataTable(lst.ToString()), startIndex + count, totalColumns, ws);
}
count = 1;
lst.Clear();
ctrl = ws.Cells[i + 2, startIndex];
lst.Add(ws.Cells[i, 1]);
}
}
if (count > 1)
{
ws.Cells[startIndex + 1, 1, startIndex + count, 1].Merge = true;
mergeCells(new DataTable(lst.ToString()), startIndex + count, totalColumns - 1, ws);
}
count = 1;
lst.Clear();
}

I have done like this:
public void WriteDataToSheet(DataTable data)
{
using (ExcelPackage excel = new ExcelPackage())
{
ExcelWorksheet ws = excel.Workbook.Worksheets.Add("Test");
ws.Cells["A1"].LoadFromDataTable(data, true);
ws.Cells[ws.Dimension.Address].AutoFitColumns();
var listObject = data.AsEnumerable()
.Select(x => new
{
Col1 = x.Field<string>("Col1"),
Col2 = x.Field<string>("Col2"),
Col3 = x.Field<string>("Col3")
}).ToList();
var lisa = listObject.GroupBy(x => x.Col1).
Select(x => new
{
Id = x.Key,
Quantity = x.Count(),
secondGroup = x.GroupBy(y => y.Col2)
.Select(y => new
{
ID = y.Key,
secondGroup = y.Count()
})
});
int A = 1, B = 0, C = 1, D = 0;
foreach (var item in lisa)
{
B = A + 1;
A += item.Quantity;
ws.Cells["A" + B + ":A" + A + ""].Merge = true;
ws.Cells["B" + B + ":B" + A + ""].Merge = true;
foreach (var item2 in item.secondGroup)
{
D = C + 1;
C += item2.secondGroup;
ws.Cells["C" + D + ":C" + C + ""].Merge = true;
}
}
// Save merged and modified file to the location
}
}

query is not giving correct values

SELECT
machine_id, operator_id, member_id, card_id, name, paid_amount, due_amount,
paid_date, phone_number, #curRow := #curRow + 1 AS row_number
FROM
transaction
JOIN
(SELECT #curRow := 0) r where card_id='c1' order by Row_number desc limit 3 ;
When I run this in workbench it returns the last 3 records. But in my code it returns only 2 records. What is the problem?
Here is the c# code:
String query3 = "SELECT machine_id,operator_id,member_id,card_id,name,paid_amount,due_amount,paid_date,phone_number ,#curRow := #curRow + 1 AS row_number FROM transaction JOIN (SELECT #curRow := 0) r where card_id=#card order by Row_number desc limit 4 ";
MySqlCommand command3 = new MySqlCommand(query3, con);
command3.Parameters.AddWithValue("#card", cardid);
using (MySqlDataReader rdr3 = command3.ExecuteReader())
{
if (rdr3.Read())
{
while (rdr3.Read())
{
if (count == 1)
{
AMT1 = Convert.ToDecimal(rdr3["paid_amount"].ToString());
TOT1 = rdr3["paid_date"].ToString();
}
if (count == 2)
{
AMT2 = Convert.ToDecimal(rdr3["paid_amount"].ToString());
TOT2 = rdr3["paid_date"].ToString();
}
if (count == 3)
{
AMT3 = Convert.ToDecimal(rdr3["paid_amount"].ToString());
TOT3 = rdr3["paid_date"].ToString();
}
count++;
}
Response.Write("$AMT1=" + AMT1 + "|TOT1=" + TOT1 + "|AMT2=" + AMT2 + "|TOT2=" + TOT2 + "|AMT3=" + AMT3 + "|TOT3=" + TOT3 + "|TS=1#");
}

You use Read() twice at the beginning and you skip the first record this way. Remove the one from if:
if (rdr3.Read())
You need just:
using (MySqlDataReader rdr3 = command3.ExecuteReader())
{
while (rdr3.Read())
{
if (count == 1)
{
AMT1 = Convert.ToDecimal(rdr3["paid_amount"].ToString());
TOT1 = rdr3["paid_date"].ToString();
}
if (count == 2)
{
AMT2 = Convert.ToDecimal(rdr3["paid_amount"].ToString());
TOT2 = rdr3["paid_date"].ToString();
}
if (count == 3)
{
AMT3 = Convert.ToDecimal(rdr3["paid_amount"].ToString());
TOT3 = rdr3["paid_date"].ToString();
}
count++;
}
Response.Write("$AMT1=" + AMT1 + "|TOT1=" + TOT1 + "|AMT2=" + AMT2 + "|TOT2=" + TOT2 + "|AMT3=" + AMT3 + "|TOT3=" + TOT3 + "|TS=1#");
}

Use if (rdr3.HasRows) instead of if (rdr3.Read())
using (MySqlDataReader rdr3 = command3.ExecuteReader())
{
if (rdr3.HasRows)
{
while (rdr3.Read())
{
if (count == 1)
{
AMT1 = Convert.ToDecimal(rdr3["paid_amount"].ToString());
TOT1 = rdr3["paid_date"].ToString();
}
if (count == 2)
{
AMT2 = Convert.ToDecimal(rdr3["paid_amount"].ToString());
TOT2 = rdr3["paid_date"].ToString();
}
if (count == 3)
{
AMT3 = Convert.ToDecimal(rdr3["paid_amount"].ToString());
TOT3 = rdr3["paid_date"].ToString();
}
count++;
}
}
Else
{
Response.Write("No rows found.");
}
Response.Write("$AMT1=" + AMT1 + "|TOT1=" + TOT1 + "|AMT2=" + AMT2 + "|TOT2=" + TOT2 + "|AMT3=" + AMT3 + "|TOT3=" + TOT3 + "|TS=1#");
}

How to validate a generic collection of Data in window Form

I have the method that does a calculation and adds the data to a collection list. Below is my code
IterateDtColl iterateDataList = new IterateDtColl();
double answer;
//Array to hold the previous initail tempreture
double[] TempArray = new double[9];
for (int tVal = 0; tVal < exdatalist.count(); tVal++)
{
ValidateDataColl validatelist = new ValidateDataColl();
//Assign my initial tempreture
if (iterateDataList.count() > 0)
{
TempArray[0] = iterateDataList.getexceldata(tVal - 1).Pi1;
TempArray[1] = iterateDataList.getexceldata(tVal - 1).Pi2;
TempArray[2] = iterateDataList.getexceldata(tVal - 1).Pi3;
TempArray[3] = iterateDataList.getexceldata(tVal - 1).Pi4;
TempArray[4] = iterateDataList.getexceldata(tVal - 1).Pi5;
TempArray[5] = iterateDataList.getexceldata(tVal - 1).Pi6;
TempArray[6] = iterateDataList.getexceldata(tVal - 1).Pi7;
TempArray[7] = iterateDataList.getexceldata(tVal - 1).Pi8;
TempArray[8] = iterateDataList.getexceldata(tVal - 1).Pi9;
}
else
{
TempArray[0] = Convert.ToDouble(initProbTxtBx.Text);
TempArray[1] = TempArray[0];
TempArray[2] = TempArray[0];
TempArray[3] = TempArray[0];
TempArray[4] = TempArray[0];
TempArray[5] = TempArray[0];
TempArray[6] = TempArray[0];
TempArray[7] = TempArray[0];
TempArray[8] = TempArray[0];
}
//Holds Value for last calculated values..
double[] LastCalValue = new double[9];
for (int iVal = 0; iVal < 9; iVal++)
{
answer = 0.0;
if (iVal == 0)
{
answer = (TempArray[iVal] + (r_val(dxval(lval, nval)) * (exdatalist.getexceldata(tVal).CentreTemp + initVal))) / (1 + (2 * r_val(dxval(lval, nval))));
}
else if (iVal == 8)
{
answer = (TempArray[iVal] + (r_val(dxval(lval, nval)) * (LastCalValue[iVal - 1] + exdatalist.getexceldata(tVal).SurfaceTemp))) / (1 + (2 * r_val(dxval(lval, nval))));
}
else
{
answer = (TempArray[iVal] + (r_val(dxval(lval, nval)) * (LastCalValue[iVal - 1] + initVal))) / (1 + (2 * r_val(dxval(lval, nval))));
}
//Hold the values at the present index so it can be used at the next index
LastCalValue[iVal] = answer;
//Adds the data to be validated to my collection list
validatelist.addvaliddt(new ValidateDataCl(initVal, LastCalValue[iVal], TempArray[iVal]));
}
I want to check that the difference between the initVal and LastCalValue[index] in the validatelist is less than 0.0001, if it is not, then do the calculation below till the condition is met.
for (int check = 0; check < validate.count(); check++)
{
double newAnswer;
double NewVal = 0.0;
if (check == 0)
{
//Set my new value to the value at the next index(Which then becomes my guess)
NewVal = validate.getvaliddata(check + 1).NewValue;
newAnswer = (validate.getvaliddata(check).InitTemp + (r_val(dxval(lval, nval)) * (CentreTemp + NewVal))) / (1 + (2 * r_val(dxval(lval, nval))));
}
else if (check == 8)
{
NewVal = OldVal[check - 1];
newAnswer = (validate.getvaliddata(check).InitTemp + (r_val(dxval(lval, nval)) * (NewVal + SurfaceTemp))) / (1 + (2 * r_val(dxval(lval, nval))));
}
else
{
NewVal = validate.getvaliddata(check + 1).NewValue;
newAnswer = (validate.getvaliddata(check).InitTemp + (r_val(dxval(lval, nval)) * (OldVal[check - 1] + NewVal))) / (1 + (2 * r_val(dxval(lval, nval))));
}
validate.getvaliddata(check).InitGuess = NewVal;
validate.getvaliddata(check).NewValue = newAnswer;
OldVal[check] = newAnswer;
}
//ValidateDataColl ValidatedList = CalNewData(validatelist, exdatalist.getexceldata(tVal).CentreTemp, exdatalist.getexceldata(tVal).SurfaceTemp);
iterateDataList.additerdt(new IterateClass(exdatalist.getexceldata(tVal).CentreTemp, ValidatedList.getvaliddata(0).NewValue, ValidatedList.getvaliddata(1).NewValue, ValidatedList.getvaliddata(2).NewValue, ValidatedList.getvaliddata(3).NewValue, ValidatedList.getvaliddata(4).NewValue, ValidatedList.getvaliddata(5).NewValue, ValidatedList.getvaliddata(6).NewValue, ValidatedList.getvaliddata(7).NewValue, ValidatedList.getvaliddata(8).NewValue, exdatalist.getexceldata(tVal).SurfaceTemp));
}
return iterateDataList;
How can I do that?