在下拉列表的基础上填充girdview [英] filling girdview on the bases of dropdownlist

问题描述

我有一个下拉列表，用于从数据库的类别表中获取数据.

ESK_Categories表

CateogoryID，类别名称.

ESK_产品表

ProductID，CategoryID(fk)，ProductName，UnitCost


现在，我想在网格视图中显示产品表中的产品.我写了代码，但给出错误，找不到表0.

请检查休假代码中绑定功能的查询..是否正确?

i have a dropdownlist getting data from the categories table in the database.

ESK_Categories Table

CateogoryID,Category name.

ESK_Products Table

ProductID,CategoryID(fk),ProductName,UnitCost


now i want to display products form the products table in the grid view. i wrote the code but its giving an error can not find table 0.

pls check the query in bind fuction in the fallowing code.. is it correct?

 dbcon obj = new dbcon();
    protected void Page_Load(object sender, EventArgs e)
    {
        //dbcon obj = new dbcon();
        if (!IsPostBack)
        {
            string querydr = "select * from ESK_Categories";
            SqlDataReader dr = obj.fillcomb(querydr);
            DropDownList1.DataSource = dr;
            DropDownList1.DataValueField = "CategoryName";
            DropDownList1.DataBind();



        }
        if (!IsPostBack)
        {
            bind();
        }

    }
    public void bind()
    {
        string query = "SELECT ESK_Products.ProductID, ESKProducts.ProductName,ESK_Products.UnitCost ,ESK_Cateogries.CategoryName FROM ESK_Products LEFT JOIN ESK_Categories ON ESK_Products.ProductsID=ESK_Categories.CategoryID Where CategoryName='" + DropDownList1.Text + "'";  
        DataSet ds = obj.fillgrid(query);
        GridView1.DataSource = ds.Tables[0];
        GridView1.DataBind();
    }
}

推荐答案

如果索引为0的表出现错误，则fillgrid方法不太可能创建/填充该表到您的数据集中.使用调试器查看方法内部发生的情况.

关于查询，如果您要获取所有产品，并且某个产品具有类别，则也要获取类别名称，那么看起来就很正确.

但是，请尝试使用 SqlParameter [

If you''re getting an error for the table indexed 0, the fillgrid method isn''t most likely creating/ filling the table into your dataset. Use the debugger to see what''s happening inside the method.

About the query, if you''re trying to fetch all products and if a product has a category then fetch the categoryname also, then it looks quite right.

However, try using SqlParameter[^] (if this is Sql Server) instead of concatenating literals into the statement (DropDownList1.Text).

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