在SQL查询中获取错误.用于基于价格过滤数据 [英] getting error in sql query. for filtering data on the bases of price

问题描述

我正在尝试根据价格对产品进行过滤...

我在一页上有一个链接控件..并且我将页面重定向到ProductCatalog.aspx，以在网格中显示产品

i am trying to filter the products on the base of price...

i have a link control on one page.. and i am redirctring the page to ProductCatalog.aspx to show the products in the grid

<td align="center">
                               <asp:LinkButton ID="LinkButton4" PostBackUrl='<%# "~/ProductCatalog.aspx?PriceID="+Eval("UnitCost") %>' runat="server"><5000</asp:LinkButton>
                           </td>

在Products.Aspx页面上

on Products.Aspx page

string query = "Select * from Products where '"+int.TryParse(Request.QueryString["PriceID"]<5000)+"'";

我收到错误消息

i am getting the error

Error 1	Operator '<' cannot be applied to operands of type 'string' and 'int'	

已改进
在产品Catalog.aspx页上

IMproved
On Product Catalog.aspx page

private void LoadGridView() // just calling it on page load
   {

       string query = "Select * from Products where UnitCost= " + Request.QueryString["ID"] + "<5000"; ;
       //DataSet ds = new DataSet();
       DataSet ds=obj.fillgrid(query);
       GridView1.DataSource = ds.Tables[0];
       GridView1.DataBind(); ;
       //conn.Close();
   }

并在我的母版页上嵌入

and on my master page i embedd

<table class="style1" width="20%">
            <tr>
                <td bgcolor="#666" align="center" class="style2" >
                    Search Products By Price Range</td>
                        </tr>
                        <tr bgcolor="#F7F7DE" >
                            <td align="center">
                                <asp:LinkButton ID="LinkButton4" PostBackUrl='<%# "~/ProductCatalog.aspx?ID="+Eval("UnitCost") %>' runat="server"><5000</asp:LinkButton>
                            </td>
                        </tr>
                        <tr bgcolor="#F7F7DE">
                            <td align="center">
                                <asp:LinkButton ID="LinkButton5" runat="server">>=5000 and <=10000</asp:LinkButton>
                            </td>
                        </tr>
                        <tr bgcolor="#F7F7DE">
                            <td align="center">
                                <asp:LinkButton ID="LinkButton6" runat="server">>=10000 and <=20000</asp:LinkButton>
                            </td>
                        </tr >
                        <tr bgcolor="#F7F7DE">
                            <td align="center">
                                <asp:LinkButton ID="LinkButton7" runat="server">>20000</asp:LinkButton>
                            </td>
                        </tr>
                    </table>

推荐答案

string query = "Select * from Products where " + Request.QueryString["PriceID"].ToString() + "<5000";

使用参数化查询
或者，您可以在DataSet或DataTable
中使用filter
编辑

---

其实Eval("UnitCost")的值是多少?因为查询中缺少字段名称(上述代码).您的代码应如下所示.

Use parametrized query
Or you can use filter in your DataSet or DataTable

EDIT

---

Actually whats the value of Eval("UnitCost")? Because the field name missing in your query(above code). You code should like below.

string query = "Select * from Products where PriceID<5000";

的产品中选择*，此处必须动态发送值5000.如果有任何问题请纠正我

EDIT2

---

因此，您想按范围选择产品吗?
您的代码应类似于(条件ProductId和UnitCost的位置应有两列)

Here you must send the value 5000 dynamically. Correct me if anything wrong

EDIT2

---

So you want to select products by range?
Your code should be like(There should be two columns in where condition ProductId & UnitCost)

string query = "Select * from Products where ProductID= '" + Request.QueryString["ID"].ToString() + "' AND UnitCost < 5000";

顺便说一句，我建议您使用参数化查询.

BTW again I suggest you to use parametrized query.

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