如何从数据库到组合框检索数据

问题描述

我正在创建桌面应用程序，在该应用程序中，我创建了一种形式，其中有三个组合框，即cboproduct，cborawmaterial_id和cborawmaterial.
我有产品，即蒸气熨斗，移动式榨汁机和榨汁机，具有相应的产品ID.
我有原材料恒温器，嵌体，ic，杯，罐，led.
我希望当我一次从cboproduct中选择一种产品时，应该在cborawmaterial中获取其各自的原材料.
我创建了2张桌子
带字段product_id和产品
的product_info具有字段product_id，rawmaterial_id和rawmaterial的rawmaterial_info

我尝试过此编码

I am creating desktop application in which i have created a form in which there are three comboboxes namely cboproduct,cborawmaterial_id and cborawmaterial.
I have products namely steamiron,mobile,juicer with respective product id.
I have rawmaterials thermostat,inlay,ic,cuplor,jar,led.
I want that when i select one product at a time from cboproduct,i should get its respective rawmaterials in cborawmaterial.
I created a 2 tables
product_info with field product_id and product
rawmaterial_info with field product_id ,rawmaterial_id and rawmaterial

I tried this coding

private void fillProductId()
        {
            SqlConnection con;
            SqlCommand com;
            String message;
            con=new SqlConnection(@"Data Source=AKMINDER-PC\SQLEXPRESS;Initial Catalog=elin appliances(Comaker of PHILIPS);Integrated Security=true");
            message
            = "Select Product_ID, Product from product_info";
            con.Open();
            DataSet DS = new DataSet();
            SqlDataAdapter DA = new SqlDataAdapter(); 
           
            DA.SelectCommand = new SqlCommand(message, con);
            com.ExecuteNonQuery();
           
            DA.Fill(DS);
            con.Close();
            if (DS.Tables[0].Rows.Count > 0)
            {
               combo1.DataSource = DS.Tables[0];
                combo1.DataTextField = "Product";
                combo1.DataValueField = "Product ID";
                combo1.DataBind();               combo1.Items.Insert(0, "--Select--");
            }
            else
            {
                lblMsg.Text = "No product found";
            }
        }

错误

error

combo1.DataTextField = "Product";
                combo1.DataValueField = "Product ID";
                combo1.DataBind();

不包含DataTextField，DataValueField，DataBind的定义，并且没有扩展方法接受类型的第一个参数(您是否缺少using指令或程序集引用?)

does not contain a definition for DataTextField ,DataValueField,DataBind and no extension method accepting a first argument of type (are you missing a using directive or an assembly reference?)

推荐答案

ComboBox1.DataSource = dsData.Tables("table1");
ComboBox1.DisplayMember = "Display Field name";
ComboBox1.ValueMember = "Value Field Name";

您的情况将是:-

In your case it will be:-

combo1.DataSource = DS.Tables[0];
combo1.DisplayMember = "Product";
combo1.ValueMember = "Product_ID";

该链接将对您有所帮助:- http://www.akadia.com/services/dotnet_databinding.html [^ ]

如果您有帮助，请不要忘记将其标记为答案.

谢谢

This link will be helpful to you:- http://www.akadia.com/services/dotnet_databinding.html[^]

Please don''t forget to mark this as your answer if it helps you out.

Thanks

combobox1.DataSource  = ds;
combobox1.DisplayMember = "EmpName";
combobox1.ValueMember = "EmpId";

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