我怎样才能插入数据后阅读

我从表中读取一些数据后，我想编辑安德编辑数据然后插入到数据库我写的这段代码，但乳宁它后，旧的数据插入数据base.what，应该怎么办？
这里是我的代码;

   protected void Page_Load(object sender, EventArgs e)

    {

           SqlCommand cmd = new SqlCommand();

       cmd.Connection = new SqlConnection(Class1.CnnStr);

       SqlDataReader reader;

 



       cmd.CommandText = "select ChequeNo,ChequeDate from table where Number=@Number";

       cmd.Connection.Open();

       cmd.Parameters.AddWithValue("@Number", Number_lbl.Text);

       reader = cmd.ExecuteReader();

 

       if (reader.Read())

       {

 

           ChequeNo_txt.Text = reader["ChequeNo"].ToString();

           ChequeDate_txt.Text = reader["ChequeDate"].ToString();

           reader.Close();

       }

       cmd.Connection.Close();

    }

    

    protected void SAVE_bt_Click(object sender, EventArgs e)

    {

        SqlCommand cmd1 = new SqlCommand();

        cmd1.Connection = new SqlConnection(Class1.CnnStr);

 

        cmd1.Connection.Open();

        cmd1.Parameters.AddWithValue("@Number", Number_lbl.Text);

        cmd1.CommandText = "update table set ChequeNo=@ChequeNo,ChequeDate=@ChequeDate where Number=@Number";

        

        cmd1.Parameters.AddWithValue("@ChequeNo",ChequeNo_txt.Text);

        cmd1.Parameters.AddWithValue("@ChequeDate", ChequeDate_txt.Text);

        cmd1.ExecuteNonQuery();

        

    }