How can I read and display selected SQL Server columns in C# DataGridView?

I want to select multiple columns from database table of SQL Server with C# windows form.

The "RollNo", "Computer", "Chemistry", "Physics", "Maths", "English", "Islamiat", "Urdu", "PakStudy" are my columns of a table "marks".

Then I have to read these columns and show their value in data grid view.

The "marks_datagrid3" is my data grid view.

I don't know why it is not running and gives error when it reads computer from database table

string query2 = "select RollNo,Computer,Chemistry,Physics,Maths,English,Islamiat,Urdu,PakStudy from marks where RollNo='" +  textBox1.Text + "'; ";

SqlCommand cmd2 = new SqlCommand(query2, con);

SqlDataReader read2 = cmd1.ExecuteReader();

while (read2.Read())
{
     marks_datagrid3.Rows[0].Cells[1].Value = read2["Computer"].ToString();
     marks_datagrid3.Rows[1].Cells[1].Value = read2["Chemistry"].ToString();
     marks_datagrid3.Rows[2].Cells[1].Value = read2["Physics"].ToString();
     marks_datagrid3.Rows[3].Cells[1].Value = read2["Maths"].ToString();
     marks_datagrid3.Rows[4].Cells[1].Value = read2["English"].ToString();
     marks_datagrid3.Rows[5].Cells[1].Value = read2["Islamiat"].ToString();
     marks_datagrid3.Rows[6].Cells[1].Value = read2["Urdu"].ToString();
     marks_datagrid3.Rows[7].Cells[1].Value = read2["PakStudy"].ToString();
}

The error is

> System.IndexOutOfRangeException

I didn't understand what you are trying to do, but I think you get the error because using the wrong SqlCommand variable.
You defined variable cmd2:

SqlCommand cmd2 = new SqlCommand(query2, con);

and used variable cmd1:

SqlDataReader read2 = cmd1.ExecuteReader();

So, change it to:

SqlDataReader read2 = cmd2.ExecuteReader();