C# CSV ดึงข้อมูลมาจาก SQL server แล้วมาเก็บไว้ใน csv และ import เข้าไป sql อีกครั้ง แต่ถ้ามีข้อมูลแล้วไม่ต้องบันทึกข้อมูลนั้น แต่ถ้าไม่ มีให้บันทึก ต้องทำอย่างไรค่ะ

			int intNumRows;
			strSQL = "SELECT COUNT(*) FROM customer WHERE CustomerID = '"+ this.txtCustomerID.Text +"' ";
			objCmd = new SqlCommand(strSQL, objConn);
			intNumRows = Convert.ToInt32(objCmd.ExecuteScalar());

			if(intNumRows > 0)
			{
				this.pnlAdd.Visible = false;
				this.lblStatus.Visible = true;
				this.lblStatus.Text = "CustomerID already exists.";
			}
			else
			{
				strSQL = "INSERT INTO customer (CustomerID,Name,Email,CountryCode,Budget,Used) " +
				" VALUES " +
				" ('" + this.txtCustomerID.Text + "','" + this.txtName.Text + "','" + this.txtEmail.Text + "', " +
				" '" + this.txtCountryCode.Text + "','" + this.txtBudget.Text + "','" + this.txtUsed.Text + "')";

				objCmd = new SqlCommand();
				objCmd.Connection = objConn;
				objCmd.CommandText = strSQL;
				objCmd.CommandType = CommandType.Text;
								
				objCmd.ExecuteNonQuery();
		}

private void exportDataTableToCsv(DataTable formattedDataTable, string filename)  
    {  
       DataTable toExcel = formattedDataTable.Copy();  
       HttpContext context = HttpContext.Current;  
       context.Response.Clear();  
      
       foreach (DataColumn column in toExcel.Columns)  
       {  
          context.Response.Write(column.ColumnName + ",");  
       }  
      
       context.Response.Write(Environment.NewLine);  
       foreach (DataRow row in toExcel.Rows)  
       {  
          for (int i = 0; i < toExcel.Columns.Count; i++)  
          {  
             context.Response.Write(row[i].ToString().Replace(",", string.Empty) + ",");  
          }  
      
          context.Response.Write(Environment.NewLine);  
       }  
      
       context.Response.ContentType = "text/csv";  
       context.Response.AppendHeader("Content-Disposition", "attachment; filename=" + filename + ".csv");  
       context.Response.End();  
    }