Insert data into Database from TextBox inside nested DataList in ASP.Net

Hi micah,

Check this example. Now please take its reference and midify it as per your requirement.

HTML

<div>
    <asp:DataList ID="GETCOMENT1" runat="server" OnItemDataBound="GETCOMENT1_ItemDataBound">
        <ItemTemplate>
            <asp:Label ID="lblId" runat="server" Text='<%#Eval("PostId") %>' Font-Bold="False"
                ForeColor="#333333" Style="display: none;" />
            <asp:Label ID="Label124" runat="server" Text='<%#Eval("MyComments") %>' Font-Bold="False"
                ForeColor="#333333" />
            <asp:DataList ID="DataListCOOMENT2" runat="server">
                <ItemTemplate>
                    <asp:TextBox ID="txtcommentpost" runat="server" Rows="1" cols="20" CssClass="txtbox form-control"
                        placeholder="Reply..." MaxLength="500" TextMode="MultiLine" BorderStyle="Solid"
                        BorderWidth="1"></asp:TextBox>
                    <asp:LinkButton ID="LinkButton2" runat="server" CssClass=" btn btn-sm" BorderColor="#CCCCCC"
                        BorderStyle="Solid" BorderWidth="1px">Post</asp:LinkButton>
                </ItemTemplate>
            </asp:DataList>
        </ItemTemplate>
    </asp:DataList>
</div>
<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script>
<script type="text/javascript">
    $(function () {
        $('[id*=LinkButton2]').on('click', function () {
            var row = $(this).closest('tr').closest('table').parent();
            var comment = $(this).closest('tr').find('[id*=txtcommentpost]').val();
            var id = $(this).closest('tr').closest('table').parent().find('[id*=lblId]').html();
            var obj = {};
            obj.id = parseInt(id);
            obj.comment = comment;
            $.ajax({
                type: "POST",
                url: "CS.aspx/Insert",
                data: JSON.stringify(obj),
                contentType: "application/json; charset=utf-8",
                dataType: "json",
                success: function (response) {
                    $(row).find('tr').eq(0).before('<tr><td>' + comment + '</td></tr>');
                    $(row).find('tr').find('[id*=txtcommentpost]').val('');
                },
                failure: function (response) {
                    alert(response.responseText);
                },
                error: function (response) {
                    alert(response.responseText);
                }
            });

            return false;
        });
    });
</script>

C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        GETCOMENT1.DataSource = GetData();
        GETCOMENT1.DataBind();
    }
}

private DataTable GetData()
{
    string constr = ConfigurationManager.ConnectionStrings["conString"].ConnectionString;
    using (SqlConnection con = new SqlConnection(constr))
    {
        using (SqlCommand cmd = new SqlCommand())
        {
            cmd.CommandText = "SELECT * FROM UserCommentPost";
            cmd.CommandType = CommandType.Text;
            cmd.Connection = con;
            SqlDataAdapter da = new SqlDataAdapter(cmd);
            DataTable dt = new DataTable();
            da.Fill(dt);

            return dt;
        }
    }
}

protected void GETCOMENT1_ItemDataBound(object sender, DataListItemEventArgs e)
{
    if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
    {
        DataList comment2 = e.Item.FindControl("DataListCOOMENT2") as DataList;
        DataTable dt = new DataTable();
        dt.Columns.AddRange(new DataColumn[] { new DataColumn("Id", typeof(int)) });
        dt.Rows.Add();
        comment2.DataSource = dt;
        comment2.DataBind();
    }
}

[WebMethod]
public static string Insert(int id, string comment)
{
    string constr = ConfigurationManager.ConnectionStrings["conString"].ConnectionString;
    using (SqlConnection con = new SqlConnection(constr))
    {
        using (SqlCommand cmd = new SqlCommand())
        {
            cmd.CommandText = "INSERT INTO UserCommentPost (PostId,MyComments) VALUES (@Id,@Comment)";
            cmd.CommandType = CommandType.Text;
            cmd.Connection = con;
            cmd.Parameters.AddWithValue("@Id", id);
            cmd.Parameters.AddWithValue("@Comment", comment);
            con.Open();
            cmd.ExecuteNonQuery();
            con.Close();
        }
    }
    return "";
}

Screenshot