Add dynamic Button and TextBox in html table each row using C# in ASP.Net

            if (!this.IsPostBack)
            {
                //Populating a DataTable from database.
                DataTable dt = this.GetData();

                //Building an HTML string.
                StringBuilder html = new StringBuilder();

                //Table start.
                html.Append("<table border = '1'>");

                //Building the Header row.
                html.Append("<tr>");
                foreach (DataColumn column in dt.Columns)
                {
                    html.Append("<th>");
                    html.Append(column.ColumnName);
                    html.Append("</th>");
                }
                html.Append("</tr>");

                //Building the Data rows.
                foreach (DataRow row in dt.Rows)
                {
                    html.Append("<tr>");
                    foreach (DataColumn column in dt.Columns)
                    {
                        html.Append("<td>");
                        html.Append(row[column.ColumnName]);
                        html.Append("</td>");
                    }
                    html.Append("</tr>");
                }
                foreach (DataRow row in dt.Rows)
                {
                    html.Append("<tr>");
                    html.Append("textbox");
                    html.Append("</tr>");
                }

                //Table end.
                html.Append("</table>");

                //Append the HTML string to Placeholder.
                PlaceHolder1.Controls.Add(new Literal { Text = html.ToString() });
            }
        private DataTable GetData()
        {
            dc.connection.Open();
            string query = "SELECT * FROM ggmims.የመጽሐፍት_መረጃ; ";
            MySqlCommand cmd = new MySqlCommand(query, dc.connection);
            MySqlDataAdapter da = new MySqlDataAdapter(cmd);
            DataTable dt = new DataTable();
            da.Fill(dt);
            dc.connection.Close();
            return dt;
            
        }