ADO.NET Classes: Part 2

The following table lists several important classes in the DataSet hierarchy and provides a brief description as well as a list of some of their important properties and methods:

Class	Description	Important Properties\Methods
DataSet	Represents a locally cached subset of the total data stored in a data source or sources and provides a relational programming model for working with that data. Includes representations of tables, constraints, and relations between tables. A DataSet object can be filled with data from multiple data sources.	Properties include: Tables — A collection of DataTable objects. Relations — A collection of DataRelation objects.
DataTable	Represents a table of data within a DataSet. A DataTable can be created programmatically or as the result of a database query. Typically, an application accesses the data in a DataSet by iterating through the Rows collection of the appropriate DataTable.	Properties include: Rows — A collection of DataRow objects. Columns — A collection of DataColumn objects.
DataRow/ DataColumn	Represent the rows and columns within DataTable object.	Use the column name to access a piece of data using syntax like the following: datum = MyDataRow["ColumnName"]
DataRelation	Represents a relation between a pair of DataTable objects within a DataSet. Possible relations include one-to-many and parent-child.	Add a DataRelation object to a DataSet Relations collection using the collection's Add method.