OleDbConnection Class

Represents an open connection to a data source.

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

public sealed class OleDbConnection : DbConnection, 
	ICloneable, IDbConnection, IDisposable

The OleDbConnection type exposes the following members.

  NameDescription
Public methodOleDbConnection()Initializes a new instance of the OleDbConnection class.
Public methodOleDbConnection(String)Initializes a new instance of the OleDbConnection class with the specified connection string.
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  NameDescription
Public propertyConnectionStringGets or sets the string used to open a database. (Overrides DbConnection.ConnectionString.)
Public propertyConnectionTimeoutGets the time to wait while trying to establish a connection before terminating the attempt and generating an error. (Overrides DbConnection.ConnectionTimeout.)
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 propertyProviderGets the name of the OLE DB provider specified in the "Provider= " clause of the connection string.
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 database transaction with the current IsolationLevel value.
Public methodBeginTransaction(IsolationLevel)Starts a database transaction with the specified isolation level.
Public methodChangeDatabaseChanges the current database for an open OleDbConnection. (Overrides DbConnection.ChangeDatabase(String).)
Public methodCloseCloses the connection to the data source. (Overrides DbConnection.Close().)
Public methodCreateCommandCreates and returns an OleDbCommand object associated with the OleDbConnection.
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 methodGetOleDbSchemaTableReturns schema information from a data source as indicated by a GUID, and after it applies the specified restrictions.
Public methodGetSchema()Returns schema information for the data source of this OleDbConnection. (Overrides DbConnection.GetSchema().)
Public methodGetSchema(String)Returns schema information for the data source of this OleDbConnection using the specified string for the schema name. (Overrides DbConnection.GetSchema(String).)
Public methodGetSchema(String, String[])Returns schema information for the data source of this OleDbConnection 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 database connection 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 OleDbConnection object pool can be released when the last underlying connection is released.
Public methodResetStateUpdates the State property of the OleDbConnection object.
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 provider 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 OleDbConnection object represents a unique connection to a data source. With a client/server database system, it is equivalent to a network connection to the server. Depending on the functionality supported by the native OLE DB provider, some methods or properties of an OleDbConnection object may not be available.

When you create an instance of OleDbConnection, all properties are set to their initial values. For a list of these values, see the OleDbConnection constructor.

You can open more than one DataReader on a single OleDbConnection. If the OLE DB provider you use does not support more than one DataReader on a single connection, the provider implicitly opens an additional connection for each.

If the OleDbConnection goes out of scope, it is not closed. Therefore, you must explicitly close the connection by calling Close or Dispose, or by using the OleDbConnection object within a Using statement.

NoteNote

To deploy high-performance applications, you must use connection pooling. When you use the .NET Framework Data Provider for OLE DB, you do not have to enable connection pooling because the provider manages this automatically. For more information about how to use connection pooling with the .NET Framework Data Provider for OLE DB, see OLE DB, ODBC, and Oracle Connection Pooling.

If a fatal OleDbException (for example, a SQL Server severity level of 20 or greater) is generated by the method executing an OleDbCommand, the OleDbConnection might be closed. However, the user can reopen the connection and continue.

An application that creates an instance of the OleDbConnection object can require all direct and indirect callers to have sufficient permission to the code by setting declarative or imperative security demands. OleDbConnection makes security demands using the OleDbPermission object. Users can verify that their code has sufficient permissions by using the OleDbPermissionAttribute object. Users and administrators can also use the Caspol.exe (Code Access Security Policy Tool) 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 server, see Connection Events.

NoteNote

The OleDbConnection object does not support setting or retrieving dynamic properties specific to an OLE DB provider. Only properties that can be passed in the connection string for the OLE DB provider are supported.

The following example creates an OleDbCommand and an OleDbConnection. The OleDbConnection is opened and set as the Connection for the OleDbCommand. The example then calls ExecuteNonQuery and closes the connection. To accomplish this, ExecuteNonQuery is passed a connection string and a query string that is an SQL INSERT statement.

public void InsertRow(string connectionString, string insertSQL)
{
    using (OleDbConnection connection = new OleDbConnection(connectionString))
    {
        // The insertSQL string contains a SQL statement that 
        // inserts a new row in the source table.
        OleDbCommand command = new OleDbCommand(insertSQL);

        // Set the Connection to the new OleDbConnection.
        command.Connection = connection;

        // Open the connection and execute the insert command. 
        try
        {
            connection.Open();
            command.ExecuteNonQuery();
        }
        catch (Exception ex)
        {
            Console.WriteLine(ex.Message);
        }
        // The connection is automatically closed when the 
        // code exits the using block.
    }
}

.NET Framework

Supported in: 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.

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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