AzamSharp

And here is the WebService that contacts the database table and gets the database based on the selection. I am also using Data Caching in the example below just to increase performance.

[WebMethod]
    public CascadingDropDownNameValue[] GetProductsByCategoryID
    (string knownCategoryValues, string category)
    {
        // Cache the results for performance 
               

        string[] categoryValues = knownCategoryValues.Split(':',';');
        int categoryID = Int32.Parse(categoryValues[1]);

        string key = "Category" + categoryID;

        DataSet ds = (DataSet)HttpContext.Current.Cache[key]; 

        if (null == ds)
        {

        ds = new DataSet(); 
            
            // We need to get the data from the database
        string query = "SELECT ProductID,ProductName FROM Products
        WHERE CategoryID = @CategoryID";
        SqlConnection myConnection = new SqlConnection
        ("Server=localhost;Database=Northwind;Trusted_Connection=true");
        SqlCommand myCommand = new SqlCommand(query, myConnection);
        myCommand.Parameters.AddWithValue("@CategoryID", categoryID); 
        SqlDataAdapter ad = new SqlDataAdapter(myCommand);        
        ad.Fill(ds); 
 
            // Put the item in the cache 
        HttpContext.Current.Cache.Insert(key, ds); 

        }

        else
        {
            ds = (DataSet) HttpContext.Current.Cache[key]; 
        }
           
       
        List<CascadingDropDownNameValue> values =
        new List<CascadingDropDownNameValue>();

        foreach (DataRow row in ds.Tables[0].Rows)
        {
            values.Add(new CascadingDropDownNameValue((string)
            row["ProductName"],row["ProductID"].ToString()));
        }

        return values.ToArray();     
    }

powered by IMHO 1.3