The DataSet Object Model

Each DataSet object contains a DataTable collection, which is made up of

individual DataTable objects. The DataTable object has both DataRow and

DataColumn collections. A single DataRow holds the actual data for one record.

The DataRow object maintains the original values and any changed values.

This information is used to determine which rows have changed during program

execution.

A DataRelation object stores information about related tables, including

which columns contain the primary keys and foreign keys that link the tables.

The Constraints collection, which belongs to the DataTable object, holds

two types of Constraint objects: Unique constraints and ForeignKey constraints.

Unique constraints enforce the requirement that values in the specified field

be unique, which is usually required for primary key fields. ForeignKey constraints

require that any foreign key value that appears in a secondary table

match a primary key value in the primary table.

Note : See “Datasets in Visual Studio Overview” in Visual Studio Help.