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OdbcConnection Class

Represents an open connection to a data source.

Namespace:  System.Data.Odbc
Assembly:  System.Data (in System.Data.dll)
public sealed class OdbcConnection : DbConnection, 
	ICloneable

The OdbcConnection type exposes the following members.

  NameDescription
Public methodOdbcConnection()Initializes a new instance of the OdbcConnection class.
Public methodOdbcConnection(String)Initializes a new instance of the OdbcConnection class with the specified connection string.
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  NameDescription
Public propertyConnectionStringGets or sets the string used to open a data source. (Overrides DbConnection.ConnectionString.)
Public propertyConnectionTimeoutGets or sets the time to wait while trying to establish a connection before terminating the attempt and generating an error.
Public propertyContainerGets the IContainer that contains the Component. (Inherited from Component.)
Public propertyDatabaseGets the name of the current database or the database to be used after a connection is opened. (Overrides DbConnection.Database.)
Public propertyDataSourceGets the server name or file name of the data source. (Overrides DbConnection.DataSource.)
Public propertyDriverGets the name of the ODBC driver specified for the current connection.
Public propertyServerVersionGets a string that contains the version of the server to which the client is connected. (Overrides DbConnection.ServerVersion.)
Public propertySiteGets or sets the ISite of the Component. (Inherited from Component.)
Public propertyStateGets the current state of the connection. (Overrides DbConnection.State.)
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  NameDescription
Public methodBeginTransaction()Starts a transaction at the data source.
Public methodBeginTransaction(IsolationLevel)Starts a transaction at the data source with the specified IsolationLevel value.
Public methodChangeDatabaseChanges the current database associated with an open OdbcConnection. (Overrides DbConnection.ChangeDatabase(String).)
Public methodCloseCloses the connection to the data source. (Overrides DbConnection.Close().)
Public methodCreateCommandCreates and returns an OdbcCommand object associated with the OdbcConnection.
Public methodCreateObjRefCreates an object that contains all the relevant information required to generate a proxy used to communicate with a remote object. (Inherited from MarshalByRefObject.)
Public methodDispose()Releases all resources used by the Component. (Inherited from Component.)
Public methodEnlistDistributedTransactionEnlists in the specified transaction as a distributed transaction.
Public methodEnlistTransactionEnlists in the specified transaction as a distributed transaction. (Overrides DbConnection.EnlistTransaction(Transaction).)
Public methodEquals(Object)Determines whether the specified object is equal to the current object. (Inherited from Object.)
Public methodGetHashCodeServes as the default hash function. (Inherited from Object.)
Public methodGetLifetimeServiceRetrieves the current lifetime service object that controls the lifetime policy for this instance. (Inherited from MarshalByRefObject.)
Public methodGetSchema()Returns schema information for the data source of this OdbcConnection. (Overrides DbConnection.GetSchema().)
Public methodGetSchema(String)Returns schema information for the data source of this OdbcConnection using the specified name for the schema name. (Overrides DbConnection.GetSchema(String).)
Public methodGetSchema(String, String[])Returns schema information for the data source of this OdbcConnection using the specified string for the schema name and the specified string array for the restriction values. (Overrides DbConnection.GetSchema(String, String[]).)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Public methodInitializeLifetimeServiceObtains a lifetime service object to control the lifetime policy for this instance. (Inherited from MarshalByRefObject.)
Public methodOpenOpens a connection to a data source with the property settings specified by the ConnectionString. (Overrides DbConnection.Open().)
Public methodOpenAsync()An asynchronous version of Open, which opens a database connection with the settings specified by the ConnectionString. This method invokes the virtual method OpenAsync with CancellationToken.None. (Inherited from DbConnection.)
Public methodOpenAsync(CancellationToken)This is the asynchronous version of Open. Providers should override with an appropriate implementation. The cancellation token can optionally be honored.The default implementation invokes the synchronous Open call and returns a completed task. The default implementation will return a cancelled task if passed an already cancelled cancellationToken. Exceptions thrown by Open will be communicated via the returned Task Exception property.Do not invoke other methods and properties of the DbConnection object until the returned Task is complete. (Inherited from DbConnection.)
Public methodStatic memberReleaseObjectPoolIndicates that the ODBC Driver Manager environment handle can be released when the last underlying connection is released.
Public methodToStringReturns a String containing the name of the Component, if any. This method should not be overridden. (Inherited from Component.)
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  NameDescription
Public eventDisposedOccurs when the component is disposed by a call to the Dispose method. (Inherited from Component.)
Public eventInfoMessageOccurs when the ODBC driver sends a warning or an informational message.
Public eventStateChangeOccurs when the state of the event changes. (Inherited from DbConnection.)
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  NameDescription
Explicit interface implemetationPrivate methodICloneable.CloneFor a description of this member, see ICloneable.Clone.
Explicit interface implemetationPrivate methodIDbConnection.BeginTransaction()Begins a database transaction. (Inherited from DbConnection.)
Explicit interface implemetationPrivate methodIDbConnection.BeginTransaction(IsolationLevel)Begins a database transaction with the specified IsolationLevel value. (Inherited from DbConnection.)
Explicit interface implemetationPrivate methodIDbConnection.CreateCommandCreates and returns a DbCommand object that is associated with the current connection. (Inherited from DbConnection.)
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An OdbcConnection object represents a unique connection to a data source created by using a connection string or ODBC data source name (DSN). With a client/server database system, it is equivalent to a network connection to the server. Depending on the functionality supported by the native ODBC driver, some methods or properties of an OdbcConnection object may not be available.

The OdbcConnection object uses native resources such as ODBC environment and connection handles. You should always explicitly close any open OdbcConnection objects by calling Close or Dispose before the OdbcConnection object goes out of scope, or by placing the connection within a Using statement. Not doing this leaves the freeing of these native resources to garbage collection. It might not free them immediately. This, in turn, can eventually cause the underlying driver to run out of resources or reach a maximum limit. This has resulted in intermittent failures. For example, you might experience Maximum Connections -related errors while many connections are waiting to be deleted by the garbage collector. Explicitly closing the connections allows for a more efficient use of native resources, enhancing scalability and improving overall application performance.

NoteNote

To deploy high-performance applications, you frequently must use connection pooling. However, when you use the .NET Framework Data Provider for ODBC, you do not have to enable connection pooling because the provider manages this automatically.

If one of the Execute methods of the OdbcCommand class causes a fatal OdbcException (for example, a SQL Server severity level of 20 or greater), the OdbcConnection may close. However, the user can reopen the connection and continue.

An application that creates an instance of the OdbcConnection object can require all direct and indirect callers to have sufficient permission to the code by setting declarative or imperative security demands. OdbcConnection creates security demands by using the OdbcPermission object. Users can verify that their code has sufficient permissions by using the OdbcPermissionAttribute object. Users and administrators can also use the Code Access Security Policy Tool (Caspol.exe) to modify security policy at the computer, user, and enterprise levels. For more information, see Code Access Security and ADO.NET.

For more information about handling warning and informational messages from the data source, see Connection Events.

The following example creates an OdbcCommand and an OdbcConnection. The OdbcConnection is opened and set as the Connection property. 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 an SQL INSERT statement.

		static private void InsertRow(string connectionString)
		{
			string queryString = 
                "INSERT INTO Customers (CustomerID, CompanyName) Values('NWIND', 'Northwind Traders')";
			OdbcCommand command = new OdbcCommand(queryString);

			using (OdbcConnection connection = new OdbcConnection(connectionString))
			{
				command.Connection = connection;
				connection.Open();
				command.ExecuteNonQuery();

                // The connection is automatically closed at  
                // the end of the Using block.
			}
		}

.NET Framework

Supported in: 4.5.1, 4.5, 4, 3.5, 3.0, 2.0, 1.1

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows Phone 8.1, Windows Phone 8, 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.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
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