What are the namespaces in which .NET has the data functionality class?

Above all namespaces are used in ADO.Net
to connect to databases.

For ex:-
System.Data -> Dataset and Datatable
Sytem.Data.SqlClient -> Sqlcommand,
sqlconnection and so on for Sql-Server DB.
System.Data.Oledb -> Oledbcommand,OledbConnection for MS-Access DB