The IDbConnection 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 IDbConnection interface directly, but creates an instance of a class that inherits IDbConnection.

Classes that inherit IDbConnection must implement all inherited members, and typically define additional members to add provider-specific functionality. For example, the IDbConnection interface defines the ConnectionTimeout property. In turn, the SqlConnection class inherits this property, and also defines the PacketSize property.

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 IDbConnection interface, you should implement the following constructors:

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.

Private Sub OpenSqlConnection()
    Dim connectionString As String = GetConnectionString()
    Using connection As New SqlConnection(connectionString)
        connection.Open()
        Console.WriteLine("ServerVersion: {0}", connection.ServerVersion)
        Console.WriteLine("State: {0}", connection.State)
    End Using
End Sub

Private Function GetConnectionString() As String
    ' To avoid storing the connection string in your code,  
    ' you can retrieve it from a configuration file, using the
    ' System.Configuration.ConfigurationSettings.AppSettings property
    Return "Data Source=(local);Database=AdventureWorks;" _
      & "Integrated Security=SSPI;"
End Function

private static void OpenSqlConnection()
{
    string connectionString = GetConnectionString();
    using (SqlConnection connection = new SqlConnection(connectionString))
    {
        connection.Open();
        Console.WriteLine("ServerVersion: {0}", connection.ServerVersion);
        Console.WriteLine("State: {0}", connection.State);
    }
}

static private string GetConnectionString()
{
    // To avoid storing the connection string in your code, 
    // you can retrieve it from a configuration file, using the 
    // System.Configuration.ConfigurationSettings.AppSettings property 
    return "Data Source=(local);Initial Catalog=AdventureWorks;"
        + "Integrated Security=SSPI;";
}

.NET Framework

.NET Framework Client Profile

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role not supported), Windows Server 2003 SP2

Reference

La interfaz IDbConnection permite que una clase heredada implemente una clase Connection, que representa una sesión única con un origen de datos (por ejemplo, una conexión de red con un servidor). Para obtener más información sobre las clases Connection, vea Conectar con un origen de datos (ADO.NET).

Una aplicación no crea una instancia de la interfaz IDbConnection directamente, sino que la crea de una clase que hereda de IDbConnection.

Las clases que heredan IDbConnection deben implementar todos los miembros heredados y suelen definir miembros adicionales para agregar la funcionalidad específica de proveedor. Por ejemplo, la interfaz IDbConnection define la propiedad ConnectionTimeout. A su vez, la clase SqlConnection hereda esta propiedad y también define la propiedad PacketSize.

Para potenciar la coherencia entre los proveedores de datos de .NET Framework, asigne a la clase heredada un nombre con el formato PrvClassname, donde Prv es el prefijo uniforme que se asigna a todas las clases de un espacio de nombres de proveedor de datos de .NET Framework específico. Por ejemplo, Sql es el prefijo de la clase SqlConnection en el espacio de nombres System.Data.SqlClient.

Al heredar de la interfaz IDbConnection, se deben implementar los siguientes constructores:

En el ejemplo siguiente se crean instancias de las clases derivadas SqlCommand y SqlConnection. Se abre SqlConnection y se establece como Connection para SqlCommand. A continuación, en el ejemplo se llama a ExecuteNonQuery y se cierra la conexión. Para ello, se pasa a ExecuteNonQuery una cadena de conexión y una cadena de consulta que es una instrucción Transact-SQL INSERT.

Private Sub OpenSqlConnection()
    Dim connectionString As String = GetConnectionString()
    Using connection As New SqlConnection(connectionString)
        connection.Open()
        Console.WriteLine("ServerVersion: {0}", connection.ServerVersion)
        Console.WriteLine("State: {0}", connection.State)
    End Using
End Sub

Private Function GetConnectionString() As String
    ' To avoid storing the connection string in your code,  
    ' you can retrieve it from a configuration file, using the
    ' System.Configuration.ConfigurationSettings.AppSettings property
    Return "Data Source=(local);Database=AdventureWorks;" _
      & "Integrated Security=SSPI;"
End Function

private static void OpenSqlConnection()
{
    string connectionString = GetConnectionString();
    using (SqlConnection connection = new SqlConnection(connectionString))
    {
        connection.Open();
        Console.WriteLine("ServerVersion: {0}", connection.ServerVersion);
        Console.WriteLine("State: {0}", connection.State);
    }
}

static private string GetConnectionString()
{
    // To avoid storing the connection string in your code, 
    // you can retrieve it from a configuration file, using the 
    // System.Configuration.ConfigurationSettings.AppSettings property 
    return "Data Source=(local);Initial Catalog=AdventureWorks;"
        + "Integrated Security=SSPI;";
}

.NET Framework

.NET Framework Client Profile

Windows 7, Windows Vista SP1 o posterior, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (no se admite Server Core), Windows Server 2008 R2 (se admite Server Core con SP1 o posterior), Windows Server 2003 SP2

Referencia