Chapter 6. DataSets
DataSet is a
memory-resident representation of data including tables,
relationships between the tables, and both unique and foreign key
constraints. It is used for working with and transporting data in a
There are four important characteristics of the
It’s not provider-specific. It’s impossible to tell by looking at the
DataSet, or at the objects contained within the
DataSet, which provider was used to retrieve the data or what the original data source was. The
DataSetprovides a consistent programming model regardless of the data source.
It’s always disconnected. Information is retrieved from the data source and placed in the
DataSetusing another ADO.NET object—the
DataAdapter. At no point does a
DataSetdirectly reference a
It can track changes made to its data. The
DataSetcontains multiple versions of each row of data in the tables, which allows changes to be updated back to the data source using a
DataAdapterobject, changes to be cancelled, and XML DiffGrams of the changes to be created.
It can contain multiple tables. Unlike the traditional ADO
DataSetapproximates a relational database in memory.
exist as both untyped and
strongly typed. Strongly typed
DataSets are a collection of automatically
generated classes that inherit from the
and provide additional properties, methods, and events based on the
DataSet schema. A strongly ...