嘗試了幾種往資料庫插入資料的方式

嗯,剛剛嘗試了幾種往資料庫插入資料的方式,記錄一下:
這裡aspx頁面上有兩個TextBox控制項,名稱分別為userName 和 pwd.還有一個submit按鈕,以下代碼都是寫在按鈕的時間中的:(如下)

1.直接用SqlCommand寫sql語句:          String strusername = this.userName.Text;
        String strpwd = this.pwd.Text;        

          SqlConnection conn = new SqlConnection();
        SqlCommand comm = new SqlCommand();
       
        conn = new SqlConnection("server=localhost;database=demo;uid=sa;pwd=123456");
        conn.Open();
        comm.Connection = conn;
        comm.CommandText = "insert into demo(username,pwd) values('" + strusername + "','" + strpwd + "')";
        comm.ExecuteNonQuery();

2.用SqlDataAdapter和DataTable:        SqlConnection conn = new SqlConnection();
        SqlCommand comm = new SqlCommand();
        SqlDataAdapter dataAdapter = new SqlDataAdapter();
        
          String strusername = this.userName.Text;
        String strpwd = this.pwd.Text;

        conn = new SqlConnection("server=localhost;database=demo;uid=sa;pwd=123456");
        conn.Open();
        comm = new SqlCommand("select * from demo", conn);
        dataAdapter.SelectCommand = comm;
        dataAdapter.InsertCommand = new SqlCommandBuilder(dataAdapter).GetInsertCommand();
        DataTable dataTable = new DataTable();
        dataAdapter.Fill(dataTable);
        DataRow dataRow = dataTable.NewRow();
        dataRow[1] = strusername;
        dataRow[2] = strpwd;
        dataTable.Rows.Add(dataRow);
        dataAdapter.Update(dataTable);

3.用SqlDataAdapter和DataSet:        SqlConnection conn = new SqlConnection();
        SqlCommand comm = new SqlCommand();
        SqlDataAdapter dataAdapter = new SqlDataAdapter();

        String strusername = this.userName.Text;
        String strpwd = this.pwd.Text;

        conn = new SqlConnection("server=localhost;database=demo;uid=sa;pwd=123456");
        conn.Open();
        comm = new SqlCommand("select * from demo", conn);
        dataAdapter.SelectCommand = comm;
        dataAdapter.InsertCommand = new SqlCommandBuilder(dataAdapter).GetInsertCommand();
        dataAdapter.Fill(dataSet);
        DataRow dataRow = dataSet.Tables[0].NewRow();
        dataRow[1] = strusername;
        dataRow[2] = strpwd;
        dataSet.Tables[0].Rows.Add(dataRow);
        dataAdapter.Update(dataSet);

OK,超級簡單吧,哦是菜鳥~~~じゃあ、一緒に頑張ろう！