Hiiii....i have the following code for updating database but am gettin error like "Object reference not set to an instance of an object" please help me..
private void btnUpdate_Click(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection();
SqlCommand cmd = new SqlCommand();
SqlDataAdapter da = new SqlDataAdapter();
string strConnection = "Integrated Security=SSPI;Persist Security Info=False;User ID=CRYSYS1-DESKTOP\\SQLEXPRESS\\Student;Initial Catalog=ipRFID;Data Source=CRYSYS1-DESKTOP\\SQLEXPRESS";
con = new SqlConnection(strConnection);
con.Open();
string command = "UPDATE TB_EmployeeMaster set Version=@Version,Operating System=@OS,Processor=@Processor,RAM=@RAM where RecId='" + txtID.Text + "'";
cmd = new SqlCommand(command,da.SelectCommand.Connection);
cmd.Parameters.AddWithValue("@RecId", txtID.Text);
cmd.Parameters.AddWithValue("@Version", txtVersion.Text);
cmd.Parameters.AddWithValue("@OS", txtOS.Text);
cmd.Parameters.AddWithValue("@Processor", txtProcessor.Text);
cmd.Parameters.AddWithValue("@RAM", txtRAM.Text);
DataSet ds = new DataSet();
da.UpdateCommand = cmd;
da.Fill(ds, "TB_EmployeeMaster");
da.Update(ds, "TB_EmployeeMaster");
//cmd.ExecuteNonQuery();
MessageBox.Show("Updated");
con.Close();
}