OdbcConnection OdbcConnection OdbcConnection OdbcConnection Class

Definition

Represents an open connection to a data source.

public ref class OdbcConnection sealed : System::Data::Common::DbConnection, ICloneable
public sealed class OdbcConnection : System.Data.Common.DbConnection, ICloneable
type OdbcConnection = class
    inherit DbConnection
    interface ICloneable
Public NotInheritable Class OdbcConnection
Inherits DbConnection
Implements ICloneable
Inheritance
Implements

Examples

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.
	}
}
Private Sub InsertRow(ByVal connectionString As String)

    Dim queryString As String = _
        "INSERT INTO Customers (CustomerID, CompanyName) Values('NWIND', 'Northwind Traders')"
    Dim command As New OdbcCommand(queryString)

    Using connection As New OdbcConnection(connectionString)
        command.Connection = connection
        connection.Open()
        command.ExecuteNonQuery()

        ' The connection is automatically closed at 
        ' the end of the Using block.
    End Using
End Sub

Remarks

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.

Note

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.

Constructors

OdbcConnection() OdbcConnection() OdbcConnection() OdbcConnection()

Initializes a new instance of the OdbcConnection class.

OdbcConnection(String) OdbcConnection(String) OdbcConnection(String) OdbcConnection(String)

Initializes a new instance of the OdbcConnection class with the specified connection string.

Properties

CanRaiseEvents CanRaiseEvents CanRaiseEvents CanRaiseEvents

Gets a value indicating whether the component can raise an event.

(Inherited from Component)
ConnectionString ConnectionString ConnectionString ConnectionString

Gets or sets the string used to open a data source.

ConnectionTimeout ConnectionTimeout ConnectionTimeout ConnectionTimeout

Gets or sets the time to wait while trying to establish a connection before terminating the attempt and generating an error.

Container Container Container Container

Gets the IContainer that contains the Component.

(Inherited from Component)
Database Database Database Database

Gets the name of the current database or the database to be used after a connection is opened.

DataSource DataSource DataSource DataSource

Gets the server name or file name of the data source.

DesignMode DesignMode DesignMode DesignMode

Gets a value that indicates whether the Component is currently in design mode.

(Inherited from Component)
Driver Driver Driver Driver

Gets the name of the ODBC driver specified for the current connection.

Events Events Events Events

Gets the list of event handlers that are attached to this Component.

(Inherited from Component)
ServerVersion ServerVersion ServerVersion ServerVersion

Gets a string that contains the version of the server to which the client is connected.

Site Site Site Site

Gets or sets the ISite of the Component.

(Inherited from Component)
State State State State

Gets the current state of the connection.

Methods

BeginTransaction() BeginTransaction() BeginTransaction() BeginTransaction()

Starts a transaction at the data source.

BeginTransaction(IsolationLevel) BeginTransaction(IsolationLevel) BeginTransaction(IsolationLevel) BeginTransaction(IsolationLevel)

Starts a transaction at the data source with the specified IsolationLevel value.

ChangeDatabase(String) ChangeDatabase(String) ChangeDatabase(String) ChangeDatabase(String)

Changes the current database associated with an open OdbcConnection.

Close() Close() Close() Close()

Closes the connection to the data source.

CreateCommand() CreateCommand() CreateCommand() CreateCommand()

Creates and returns an OdbcCommand object associated with the OdbcConnection.

CreateObjRef(Type) CreateObjRef(Type) CreateObjRef(Type) CreateObjRef(Type)

Creates an object that contains all the relevant information required to generate a proxy used to communicate with a remote object.

(Inherited from MarshalByRefObject)
Dispose() Dispose() Dispose() Dispose()

Releases all resources used by the Component.

(Inherited from Component)
Dispose(Boolean) Dispose(Boolean) Dispose(Boolean) Dispose(Boolean)

Releases the unmanaged resources used by the Component and optionally releases the managed resources.

(Inherited from Component)
EnlistDistributedTransaction(ITransaction) EnlistDistributedTransaction(ITransaction) EnlistDistributedTransaction(ITransaction) EnlistDistributedTransaction(ITransaction)

Enlists in the specified transaction as a distributed transaction.

EnlistTransaction(Transaction) EnlistTransaction(Transaction) EnlistTransaction(Transaction) EnlistTransaction(Transaction)

Enlists in the specified transaction as a distributed transaction.

Equals(Object) Equals(Object) Equals(Object) Equals(Object)

Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetHashCode() GetHashCode() GetHashCode() GetHashCode()

Serves as the default hash function.

(Inherited from Object)
GetLifetimeService() GetLifetimeService() GetLifetimeService() GetLifetimeService()

Retrieves the current lifetime service object that controls the lifetime policy for this instance.

(Inherited from MarshalByRefObject)
GetSchema() GetSchema() GetSchema() GetSchema()

Returns schema information for the data source of this OdbcConnection.

GetSchema(String) GetSchema(String) GetSchema(String) GetSchema(String)

Returns schema information for the data source of this OdbcConnection using the specified name for the schema name.

GetSchema(String, String[]) GetSchema(String, String[]) GetSchema(String, String[]) GetSchema(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.

GetService(Type) GetService(Type) GetService(Type) GetService(Type)

Returns an object that represents a service provided by the Component or by its Container.

(Inherited from Component)
GetType() GetType() GetType() GetType()

Gets the Type of the current instance.

(Inherited from Object)
InitializeLifetimeService() InitializeLifetimeService() InitializeLifetimeService() InitializeLifetimeService()

Obtains a lifetime service object to control the lifetime policy for this instance.

(Inherited from MarshalByRefObject)
MemberwiseClone() MemberwiseClone() MemberwiseClone() MemberwiseClone()

Creates a shallow copy of the current Object.

(Inherited from Object)
MemberwiseClone(Boolean) MemberwiseClone(Boolean) MemberwiseClone(Boolean) MemberwiseClone(Boolean)

Creates a shallow copy of the current MarshalByRefObject object.

(Inherited from MarshalByRefObject)
Open() Open() Open() Open()

Opens a connection to a data source with the property settings specified by the ConnectionString.

ReleaseObjectPool() ReleaseObjectPool() ReleaseObjectPool() ReleaseObjectPool()

Indicates that the ODBC Driver Manager environment handle can be released when the last underlying connection is released.

ToString() ToString() ToString() ToString()

Returns a String containing the name of the Component, if any. This method should not be overridden.

(Inherited from Component)

Events

Disposed Disposed Disposed Disposed

Occurs when the component is disposed by a call to the Dispose() method.

(Inherited from Component)
InfoMessage InfoMessage InfoMessage InfoMessage

Occurs when the ODBC driver sends a warning or an informational message.

StateChange StateChange StateChange StateChange

Explicit Interface Implementations

ICloneable.Clone() ICloneable.Clone() ICloneable.Clone() ICloneable.Clone()

For a description of this member, see Clone().

IDbConnection.BeginTransaction() IDbConnection.BeginTransaction() IDbConnection.BeginTransaction() IDbConnection.BeginTransaction()
IDbConnection.BeginTransaction(IsolationLevel) IDbConnection.BeginTransaction(IsolationLevel) IDbConnection.BeginTransaction(IsolationLevel) IDbConnection.BeginTransaction(IsolationLevel)
IDbConnection.CreateCommand() IDbConnection.CreateCommand() IDbConnection.CreateCommand() IDbConnection.CreateCommand()

Applies to

See Also