Export (0) Print
Expand All

IDbConnection Interface

Represents an open connection to a data source, and is implemented by .NET Framework data providers that access relational databases.

Namespace:  System.Data
Assembly:  System.Data (in System.Data.dll)

public interface IDbConnection : IDisposable

The IDbConnection type exposes the following members.

  NameDescription
Public propertySupported by the XNA FrameworkConnectionStringGets or sets the string used to open a database.
Public propertySupported by the XNA FrameworkConnectionTimeoutGets the time to wait while trying to establish a connection before terminating the attempt and generating an error.
Public propertySupported by the XNA FrameworkDatabaseGets the name of the current database or the database to be used after a connection is opened.
Public propertySupported by the XNA FrameworkStateGets the current state of the connection.
Top

  NameDescription
Public methodSupported by the XNA FrameworkBeginTransaction()Begins a database transaction.
Public methodSupported by the XNA FrameworkBeginTransaction(IsolationLevel)Begins a database transaction with the specified IsolationLevel value.
Public methodSupported by the XNA FrameworkChangeDatabaseChanges the current database for an open Connection object.
Public methodSupported by the XNA FrameworkCloseCloses the connection to the database.
Public methodSupported by the XNA FrameworkCreateCommandCreates and returns a Command object associated with the connection.
Public methodSupported by the XNA FrameworkDisposePerforms application-defined tasks associated with freeing, releasing, or resetting unmanaged resources. (Inherited from IDisposable.)
Public methodSupported by the XNA FrameworkOpenOpens a database connection with the settings specified by the ConnectionString property of the provider-specific Connection object.
Top

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 in 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.

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 IDbConnection interface, you should implement the following constructors:

Item

Description

PrvConnection()

Initializes a new instance of the PrvConnection class.

PrvConnection(string connectionString)

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.

using System;
using System.Data;

namespace IDbConnectionSample {
   class Program {
      static void Main(string[] args) {
         IDbConnection connection;

         // First use a SqlClient connection
         connection = new System.Data.SqlClient.SqlConnection(@"Server=(localdb)\V11.0");
         Console.WriteLine("SqlClient\r\n{0}", GetServerVersion(connection));
         connection = new System.Data.SqlClient.SqlConnection(@"Server=(local);Integrated Security=true");
         Console.WriteLine("SqlClient\r\n{0}", GetServerVersion(connection));

         // Call the same method using ODBC 
         // NOTE: LocalDB requires the SQL Server 2012 Native Client ODBC driver
         connection = new System.Data.Odbc.OdbcConnection(@"Driver={SQL Server Native Client 11.0};Server=(localdb)\v11.0");
         Console.WriteLine("ODBC\r\n{0}", GetServerVersion(connection));
         connection = new System.Data.Odbc.OdbcConnection(@"Driver={SQL Server Native Client 11.0};Server=(local);Trusted_Connection=yes");
         Console.WriteLine("ODBC\r\n{0}", GetServerVersion(connection));

         // Call the same method using OLE DB
         connection = new System.Data.OleDb.OleDbConnection(@"Provider=SQLNCLI11;Server=(localdb)\v11.0;Trusted_Connection=yes;");
         Console.WriteLine("OLE DB\r\n{0}", GetServerVersion(connection));
         connection = new System.Data.OleDb.OleDbConnection(@"Provider=SQLNCLI11;Server=(local);Trusted_Connection=yes;");
         Console.WriteLine("OLE DB\r\n{0}", GetServerVersion(connection));
         }

      public static string GetServerVersion(IDbConnection connection) {
         // Ensure that the connection is opened (otherwise executing the command will fail)
         ConnectionState originalState = connection.State;
         if (originalState != ConnectionState.Open)
            connection.Open();
         try {
            // Create a command to get the server version 
            // NOTE: The query's syntax is SQL Server specific
            IDbCommand command = connection.CreateCommand();
            command.CommandText = "SELECT @@version";
            return (string)command.ExecuteScalar();
         }
         finally {
            // Close the connection if that's how we got it 
            if (originalState == ConnectionState.Closed)
               connection.Close();
         }
      }
   }
}

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Show:
© 2014 Microsoft