ADO.NET in a Nutshell

Shaping DataSet XML

The default format used for the DataSet XML works perfectly well when you create a new cross-platform application. However, most systems include legacy clients that require data in a set format. Unfortunately, even a minute difference between the expected and the actual XML file format can prevent a client from successfully reading the data.

ADO.NET offers limited ways to customize the generated XML for a DataSet. Before writing your own custom code, you should begin by examining these features. If you need to perform more significant changes, you need to perform these additional operations using the .NET XML classes or XLST transformation.

Attributes and Elements

One recurring question in XML modeling is the question of whether to use attributes to store data or contained elements. For example, here’s a category row that uses only elements:

<Categories>

  <CategoryID>1</CategoryID>

  <CategoryName>Beverages</CategoryName>

  <Description>Soft drinks, coffees, teas, beers, and ales</Description>

</Categories>

And here’s the same row with attributes:

<Categories CategoryID="1" CategoryName="Beverages"

 Description="Soft drinks, coffees, teas, beers, and ales" />

With ADO.NET, you can configure whether column values are stored in attributes or elements. Best of all, you can do it on a per-column basis (for example, storing the unique identity column as an attribute and all other columns as elements). All you need to do is set the DataColumn.ColumnMapping property to one of the ...