ASP.NET C＃MySql选择并更新表单

Question

Here i Got some code i tried lot of method, I just able to display the data into my form by using Select query but Am not able to update it, it updating but it just updating old value not new value i changed in textbox

Here is the form

 <%@ Page Language="C#" AutoEventWireup="true" CodeFile="Editcar.aspx.cs" MasterPageFile="MasterPage2.master" Inherits ="Editcar" %>


<asp:Content ID="formContent" ContentPlaceHolderID="ContentPlaceHolder1" runat="server">



 <br />
 <br />
 <br />

<div class="row container">

 <form id="form1" runat="server" class="col-md-10" action="update.aspx" methode="post" >


    <asp:Table ID="GridView1" class="nav-justified" runat="server" AutoGenerateColumns="false" Height="628px" Width="763px">
        <asp:TableRow>
           <asp:TableCell>
                <h4> Car name:</h4>

           </asp:TableCell>
           <asp:TableCell>
                <asp:TextBox ID="id" runat="server" name="id" Width="301px" Text='<%# Eval("id") %>' Visible="False" CssClass="form-control"></asp:TextBox>
                <asp:TextBox ID="carmake" runat="server" Font-Names="carmake" Width="301px" Text='<%#  Eval("car_make") %>' CssClass="form-control"></asp:TextBox>

           </asp:TableCell>
        </asp:TableRow>
        <asp:TableRow>
           <asp:TableCell>
                <h4> Car model:</h4>
           </asp:TableCell>
           <asp:TableCell>
                <asp:TextBox ID="carmodel" runat="server" name="carmodel" Text='<%#  Eval("car_model") %>' Width="301px" CssClass="form-control"></asp:TextBox>
           </asp:TableCell>
        </asp:TableRow>
        <asp:TableRow>
           <asp:TableCell>
                <h4> Price: </h4>
           </asp:TableCell>
           <asp:TableCell>
                <asp:TextBox ID="price"  name="price" runat="server" Width="301px"  CssClass="form-control"></asp:TextBox>
           </asp:TableCell>
        </asp:TableRow>
        <asp:TableRow>
           <asp:TableCell>
                <h4> Discounted Price If: </h4>
           </asp:TableCell>
           <asp:TableCell>
                <asp:TextBox ID="d_price" name="d_price" runat="server" Width="301px"  CssClass="form-control"/>
           </asp:TableCell></asp:TableRow><asp:TableRow>
           <asp:TableCell> <h4>Car image (Type url)</h4></asp:TableCell><asp:TableCell>
                <asp:TextBox CssClass="form-control" ID="image"  name="image" runat="server" />Just Location
            </asp:TableCell></asp:TableRow><asp:TableRow>
           <asp:TableCell><h4>Avilability</h4></asp:TableCell><asp:TableCell>
                 <asp:TextBox CssClass="form-control" ID="avail"  name="avail" runat="server" />Just Location
           </asp:TableCell></asp:TableRow><asp:TableRow>
           <asp:TableCell><h4>Quantity</h4></asp:TableCell><asp:TableCell>
                 <asp:TextBox CssClass="form-control" ID="quantity"   name="quantity" runat="server" />Just Location
           </asp:TableCell></asp:TableRow><asp:TableRow>
           <asp:TableCell>
                <h4>Long description </h4>
           </asp:TableCell><asp:TableCell>

                <asp:TextBox ID="details" name="details" runat="server" Width="295px"  CssClass="form-control" Height="81px" TextMode="MultiLine"></asp:TextBox>
           </asp:TableCell></asp:TableRow><asp:TableRow>
           <asp:TableCell>
                <h4>Year </h4>
           </asp:TableCell><asp:TableCell>
                <asp:TextBox ID="year" name="year" runat="server" Width="295px"  CssClass="form-control" ></asp:TextBox>
           </asp:TableCell></asp:TableRow><asp:TableRow>
           <asp:TableCell>
                <h4>Special Discounted(0 0r 1) </h4>
           </asp:TableCell><asp:TableCell>
                <asp:TextBox ID="special" name="special"  runat="server" Width="295px"  CssClass="form-control"  ></asp:TextBox>
           </asp:TableCell></asp:TableRow></asp:Table><asp:Button ID="button"  runat="server"  Cssclass="btn btn-primary btn-lg btn-block" Text="Update the car" />


<br />
   <br />

   </form>


</div>
</asp:Content>

Here is the CS file

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Configuration;
using System.Data;
using MySql.Data.MySqlClient;

public partial class Editcar : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;

        using (MySqlConnection con = new MySqlConnection(constr))
    {
        var id = Request.QueryString["id"];
        string selectquery = "SELECT * FROM product WHERE id=" + @id;
        MySqlCommand cmd = new MySqlCommand(selectquery);
        cmd.Connection = con;
        cmd.CommandType = CommandType.Text;
        con.Open();
        cmd.ExecuteNonQuery();

        MySqlDataAdapter da = new MySqlDataAdapter(cmd);
        DataTable dt = new DataTable();
        da.Fill(dt);

        foreach (DataRow dr in dt.Rows)

        {

            id = dr["id"].ToString();
            carmake.Text = dr["car_make"].ToString();
            carmodel.Text = dr["car_model"].ToString();
            price.Text = dr["unitprice"].ToString();
            d_price.Text = dr["discountprice"].ToString();
            image.Text = dr["image"].ToString();
            quality.Text = dr["quantity"].ToString();
            avil.Text = dr["availability"].ToString();
            details.Text = dr["details"].ToString();
            year.Text = dr["year"].ToString();
            special.Text = dr["special"].ToString();



        }
    }
}
}

Here his the update page cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using System.Configuration;
using MySql.Data.MySqlClient;

public partial class AdminGroup_Update: System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        string constor = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
        MySqlConnection conn = new MySqlConnection(constor);
        var id = Request.QueryString["id"];
        var carmake = Request.QueryString["carmake"];
        var carmodel = Request.QueryString["carmodel"];
        var price = Request.QueryString["price"];
        var d_price = Request.QueryString["d_price"];
        var image = Request.QueryString["image"];
        var quantity = Request.QueryString["quantity"];
        var avail = Request.QueryString["avail"];
        var details = Request.QueryString["details"];
        var year = Request.QueryString["year"];
        var special = Request.QueryString["special"];

        string sql = "Update product SET car_make=@carmake ,car_model=@carmodel ,UnitPrice=@price ,Discountprice=@d_price ,image=@image ,Quantity=@quality ,availability=@avil ,details=@details ,year=@year ,special=@special  WHERE id= @id";



        var cmd = new MySqlCommand(sql, conn);


            conn.Open();
            cmd.CommandType = CommandType.Text;
            var param = new MySqlParameter[10];

            param[0] = new MySqlParameter("@carmake", MySqlDbType.VarChar, 100);
            param[1] = new MySqlParameter("@carmodel", MySqlDbType.VarChar, 100);
            param[2] = new MySqlParameter("@price", MySqlDbType.VarChar, 100);
            param[3] = new MySqlParameter("@d_price", MySqlDbType.VarChar, 100); // put zero if no discount
            param[4] = new MySqlParameter("@image", MySqlDbType.VarChar, 300);
            param[5] = new MySqlParameter("@quantity", MySqlDbType.VarChar, 300);
            param[6] = new MySqlParameter("@avail", MySqlDbType.VarChar, 2);
            param[7] = new MySqlParameter("@details", MySqlDbType.VarChar, 2000);
            param[8] = new MySqlParameter("@year", MySqlDbType.VarChar, 4);
            param[9] = new MySqlParameter("@special", MySqlDbType.VarChar, 2);
            param[10] = new MySqlParameter("@id", MySqlDbType.VarChar, 2);

            param[0].Value = carmake;
            param[1].Value = carmodel;
            param[2].Value = price;
            param[3].Value = d_price;
            param[4].Value = image;
            param[5].Value = quality;
            param[6].Value = avil;
            param[7].Value = details;
            param[8].Value = year;
            param[9].Value = special;
            param[10].Value =id;

            var ex = cmd.ExecuteNonQuery();

            if (ex == 1)
            {
                Response.Redirect("AdminList.aspx");
            }
            else
            {
                Response.Write("Error");
            }
            conn.Close();


    }

}

Answer 1

Your button

 <asp:Button ID="button"  runat="server"  
             Cssclass="btn btn-primary btn-lg btn-block" 
             Text="Update the car" />

needs an OnClick setting and an event handler in your code-behind .cs file to handle it.

Webforms / dot net works differently from some other interactive web page frameworks in that most controls post back to the same page rather than posting to another page. So, you don't need a separate update page, and indeed won't be able to use it in the normal course of event processing.