我想显示所选下拉列表项的价格。 [英] i want to show price of selected dropdownlist item.

问题描述

我做了两个下拉菜单和一个标签。



1.ddCategory下拉菜单

2.ddProduct下拉菜单

3.价格优惠



i hvae数据库中有3个表。第一个是CategoryData第二个是ProductData，第三个是PriceData



CAtegoryData数据绑定到ddCategory //（Id，CAtegory_Id，Name）4个类别

ProductData数据绑定到ddProduct //（（Id，Category_Id，Product_Name）8每个类别中的产品

Pricedata有价格。（Id，Category_Id，Price）



用户选择类别。产品显示所选类别。然后价格应显示在标签上。



i无法显示价格进入标签。



i猜我的选择声明错了。



这里的代码，请尽快帮助

i made two dropdowns and 1 lable.

1.ddCategory dropdown
2.ddProduct dropdown
3.Price lable

i hvae 3 tables in database. 1st is CategoryData 2nd is ProductData and 3rd is is PriceData

CAtegoryData is databound to ddCategory // (Id,CAtegory_Id,Name)4 categories
ProductData is databound to ddProduct // ((Id,Category_Id,Product_Name)8 Product in each category
Pricedata has price. (Id,Category_Id,Price)

user select category. product are shown of the selected category. and then the price should be displayed on the lable.

i just couldn't display price into the lable.

i guess my select statement is wrong.

code here, please help asap

SqlCommand cmd = new SqlCommand("Select * From PriceData Where Id ='" + ddCategory.SelectedValue + "'", con);

       cmd.Parameters.AddWithValue("@Price", ddProduct.SelectedItem.Value);
       cmd.CommandType = CommandType.Text;

       cmd.Connection = con;
       SqlDataReader sdr = cmd.ExecuteReader();

       if (sdr.Read())
       {

           Price.Text = sdr["Price"].ToString();
       }

推荐答案

这可以解决您的问题。

This should resolve your problem.

SqlCommand cmd = new SqlCommand("Select * From PriceData Where Id =" + ddProduct.SelectedValue.ToString(), con);
        cmd.CommandType = CommandType.Text; 
        cmd.Connection = con;
        string price = cmd.ExecuteScalar();
        
        if (!price.Equals(String.Empty))
        { 
            Price.Text = price;
        }   

假设：

PriceData表在字段Id中存储productid



如果这不能解决问题，请告诉我！

Assumption:
PriceData table is storing productid in the field Id

In case this doesn't resolve the issue, please let me know !

这篇关于我想显示所选下拉列表项的价格。的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！