Conclusion
That's all there is to it. For simple uses, this method of storing and
retrieving information may be much easier than using a database, however,
there are a few things you should keep in mind. First, our simple XML
document stores all data as text strings. This isn't too much of a problem
since we can use the .NET data types to parse our string data to other types
like integer and datetime, but remember when you pass the key value to the
Find method that it needs to be a string. Second, if we only want one "row"
of data returned for a lookup key, we need to ensure that we don't duplicate
the key in our XML document--in a database we could easily enforce this by
setting the column to be an identity column.
If you are using this method in a busy ASP.NET application where you have a
relatively small amount of data and your data doesn't change too often, you
may want to store the DataSet object in cache so the XML document doesn't
need to be read and parsed for each request. Use a CacheDependency on the
XML file to ensure that the cache is expired when the document is updated.
Download the following for complete code in a console application:
using
System
;
using
System
.
Data
;
namespace
productsxml
{
/// <summary>
/// Summary description for Class1.
/// </summary>
classmain
{
/// <summary>
/// The main entry point for the application.
/// </summary>
[STAThread]
static voidMain(string[]args)
{
//
// TODO: Add code to start application here
//
DataSet dsProducts=newDataSet();
dsProducts.ReadXml("productlist.xml");
DataView dvProducts=new
DataView(dsProducts.Tables["Products"]);
dvProducts.Sort="SKU";
introwIndex=dvProducts.Find("1");
stringPrice,Description;
if(rowIndex== -1)
{
// The SKU was not found in our data
Console.WriteLine("Product Not found");
}
else
{
Price=dvProducts[rowIndex]["Price"].ToString();
Console.WriteLine("Price: "+Price);
// Price: 100.00
Description=dvProducts[rowIndex]
["Description"].ToString();
Console.WriteLine("Description: "+Description);
// Description: Widget #1
}
}
}
}