Represents an open connection to a data source, and is implemented by .NET Framework data providers that access relational databases.
Assembly: System.Data (in System.Data.dll)
The interface enables an inheriting class to implement a Connection class, which represents a unique session with a data source (for example, a network connection to a server). For more information about Connection classes, see Connecting to a Data Source (ADO.NET).
An application does not create an instance of the interface directly, but creates an instance of a class that inherits .
Classes that inherit must implement all inherited members, and typically define additional members to add provider-specific functionality. For example, the interface defines the ConnectionTimeout property. In turn, the SqlConnection class inherits this property, and also defines the PacketSize property.Notes to Implementers:
To promote consistency among .NET Framework data providers, name the inheriting class in the form PrvClassname where Prv is the uniform prefix given to all classes in a specific .NET Framework data provider namespace. For example, Sql is the prefix of the SqlConnection class in the System.Data.SqlClient namespace.
When you inherit from the interface, you should implement the following constructors:
Initializes a new instance of the PrvConnection class.
Initializes a new instance of the PrvConnection class when given a string containing the connection string.
The following example creates instances of the derived classes, SqlCommand and SqlConnection. The SqlConnection is opened and set as the Connection for the SqlCommand. The example then calls ExecuteNonQuery, and closes the connection. To accomplish this, the ExecuteNonQuery is passed a connection string and a query string that is a Transact-SQL INSERT statement.
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.