DbConnection Class

Definition

Namespace:

System.Data.Common

Assembly:

System.Data.Common.dll

Source:

DbConnection.cs

Defines the core behavior of database connections and provides a base class for database-specific connections.

public ref class DbConnection abstract : System::ComponentModel::Component, IAsyncDisposable, IDisposable, System::Data::IDbConnection

public abstract class DbConnection : System.ComponentModel.Component, IAsyncDisposable, IDisposable, System.Data.IDbConnection

type DbConnection = class
    inherit Component
    interface IDbConnection
    interface IDisposable
    interface IAsyncDisposable

Public MustInherit Class DbConnection
Inherits Component
Implements IAsyncDisposable, IDbConnection, IDisposable

Inheritance

Object

MarshalByRefObject

Component

DbConnection

Derived

System.Data.EntityClient.EntityConnection

System.Data.Odbc.OdbcConnection

System.Data.OleDb.OleDbConnection

System.Data.SqlClient.SqlConnection

Implements

IDisposable IDbConnection IAsyncDisposable

Notes to Implementers

When you inherit from DbConnection, you must override the following members: Close(), BeginDbTransaction(IsolationLevel), ChangeDatabase(String), CreateDbCommand(), Open(), and StateChange. You must also provide the following properties: ConnectionString, Database, DataSource, ServerVersion, and State.

Constructors

DbConnection()

Initializes a new instance of the DbConnection class.

Properties

CanCreateBatch	Gets a value that indicates whether this DbConnection instance supports the DbBatch class.
CanRaiseEvents	Gets a value indicating whether the component can raise an event. (Inherited from Component)
ConnectionString	When overridden in a derived class, gets or sets the string used to open the connection.
ConnectionTimeout	Gets the time to wait (in seconds) while establishing a connection before terminating the attempt and generating an error.
Container	Gets the IContainer that contains the Component. (Inherited from Component)
Database	When overridden in a derived class, gets the name of the current database after a connection is opened, or the database name specified in the connection string before the connection is opened.
DataSource	When overridden in a derived class, gets the name of the database server to which to connect.
DbProviderFactory	Gets the DbProviderFactory for this DbConnection.
DesignMode	Gets a value that indicates whether the Component is currently in design mode. (Inherited from Component)
Events	Gets the list of event handlers that are attached to this Component. (Inherited from Component)
ServerVersion	When overridden in a derived class, gets a string that represents the version of the server to which the object is connected.
Site	Gets or sets the ISite of the Component. (Inherited from Component)
State	Gets a value that describes the state of the connection.

Methods

BeginDbTransaction(IsolationLevel)	When overridden in a derived class, starts a database transaction.
BeginDbTransactionAsync(IsolationLevel, CancellationToken)	Asynchronously starts a database transaction.
BeginTransaction()	Starts a database transaction.
BeginTransaction(IsolationLevel)	Starts a database transaction with the specified isolation level.
BeginTransactionAsync(CancellationToken)	Asynchronously begins a database transaction.
BeginTransactionAsync(IsolationLevel, CancellationToken)	Asynchronously begins a database transaction.
ChangeDatabase(String)	When overridden in a derived class, changes the current database for an open connection.
ChangeDatabaseAsync(String, CancellationToken)	Asynchronously changes the current database for an open connection.
Close()	When overridden in a derived class, closes the connection to the database.
CloseAsync()	Asynchronously closes the connection to the database.
CreateBatch()	Returns a new instance of the provider's class that implements the DbBatch class.
CreateCommand()	Creates and returns a DbCommand object associated with the current connection.
CreateDbBatch()	When overridden in a derived class, returns a new instance of the provider's class that implements the DbBatch class.
CreateDbCommand()	When overridden in a derived class, creates and returns a DbCommand object associated with the current connection.
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()	Releases all resources used by the Component. (Inherited from Component)
Dispose(Boolean)	Releases the unmanaged resources used by the Component and optionally releases the managed resources. (Inherited from Component)
DisposeAsync()	Asynchronously diposes the connection object.
EnlistTransaction(Transaction)	Enlists in the specified transaction.
Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetLifetimeService()	Obsolete. Retrieves the current lifetime service object that controls the lifetime policy for this instance. (Inherited from MarshalByRefObject)
GetSchema()	Returns schema information for the data source of this DbConnection.
GetSchema(String, String[])	Returns schema information for the data source of this DbConnection using the specified string for the schema name and the specified string array for the restriction values.
GetSchema(String)	Returns schema information for the data source of this DbConnection using the specified string for the schema name.
GetSchemaAsync(CancellationToken)	This is an asynchronous version of GetSchema(). Providers should override with an appropriate implementation. The cancellationToken can optionally be honored. The default implementation invokes the synchronous GetSchema() call and returns a completed task. The default implementation will return a cancelled task if passed an already cancelled cancellationToken. Exceptions thrown by GetSchema() will be communicated via the returned Task Exception property.
GetSchemaAsync(String, CancellationToken)	This is the asynchronous version of GetSchema(String). Providers should override with an appropriate implementation. The cancellationToken can optionally be honored. The default implementation invokes the synchronous GetSchema(String) call and returns a completed task. The default implementation will return a cancelled task if passed an already cancelled cancellationToken. Exceptions thrown by GetSchema(String) will be communicated via the returned Task Exception property.
GetSchemaAsync(String, String[], CancellationToken)	This is the asynchronous version of GetSchema(String, String[]). Providers should override with an appropriate implementation. The cancellationToken can optionally be honored. The default implementation invokes the synchronous GetSchema(String, String[]) call and returns a completed task. The default implementation will return a cancelled task if passed an already cancelled cancellationToken. Exceptions thrown by GetSchema(String, String[]) will be communicated via the returned Task Exception property.
GetService(Type)	Returns an object that represents a service provided by the Component or by its Container. (Inherited from Component)
GetType()	Gets the Type of the current instance. (Inherited from Object)
InitializeLifetimeService()	Obsolete. Obtains a lifetime service object to control the lifetime policy for this instance. (Inherited from MarshalByRefObject)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
MemberwiseClone(Boolean)	Creates a shallow copy of the current MarshalByRefObject object. (Inherited from MarshalByRefObject)
OnStateChange(StateChangeEventArgs)	Raises the StateChange event.
Open()	When overridden in a derived class, opens a database connection with the settings specified by the ConnectionString.
OpenAsync()	An asynchronous version of Open(), which opens a database connection with the settings specified by the ConnectionString. This method invokes the virtual method OpenAsync(CancellationToken) with CancellationToken.None.
OpenAsync(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.
ToString()	Returns a String containing the name of the Component, if any. This method should not be overridden. (Inherited from Component)

Events

Disposed	Occurs when the component is disposed by a call to the Dispose() method. (Inherited from Component)
StateChange	Occurs when the state of the connection changes.

Explicit Interface Implementations

IDbConnection.BeginTransaction()	Begins a database transaction.
IDbConnection.BeginTransaction(IsolationLevel)	Begins a database transaction with the specified isolation level.
IDbConnection.CreateCommand()	Creates and returns a DbCommand object that is associated with the current connection.

Extension Methods

ConfigureAwait(IAsyncDisposable, Boolean)

Configures how awaits on the tasks returned from an async disposable will be performed.

See also

• DbProviderFactories (ADO.NET)
• ADO.NET Overview