Connection

The ADO Connection object provides the means to obtain an open connection to a data source. Through this open connection, you can access and manipulate a database.

In order to query a database, you do not need to explicitly create a Connection object. A connection can be made by passing a connection string via a Command or Recordset object. However, such a connection is only good for that specific, single query. If you desire to access a data source multiple times, it is far more efficient to establish a connection using the Connection object.

In a similar vein, you can pass a query string using the Execute method of the Connection object. However, a Connection object query lacks the superior functionality of a Command object query.

Only the Connection and Recordset objects have events. Note that only the Visual Basic, Visual C++, and Visual J++ languages can handle these events. You cannot handle an event using the VBScript or JScript scripting languages.

Properties

Attributes	Sets or returns a long value defining the characteristics of a Connection object.
CommandTimeout	Sets the number of seconds to wait while attempting an Execute method call before terminating the attempt and generating an error message.
ConnectionString	Sets or returns a string value that contains the details used to create a connection to a data source.
ConnectionTimeout	Sets the number of seconds to wait while attempting to create a connection before terminating the attempt and generating an error message.
CursorLocation	Sets or returns a long value used to select between various cursor libraries accessible through the provider.
DefaultDatabase	Sets or returns a string value that is the default name of the database available from the provider for a Connection object.
IsolationLevel	Sets or returns the transaction isolation level (the IsolationLevelEnum value) of a Connection object.
Mode	Sets or returns the provider access permission (the ConnectModeEnum value) for a Connection object.
Provider	Sets or returns the string value that is the provider name.
State	Returns a long value (the ObjectStateEnum value) describing if the connection is open or closed.
Version	Returns a string value that is the ADO version number.

Methods

BeginTrans	Begins a new transaction and returns a long value indicating the number of nested transactions.
Cancel	Cancels the execution of a pending Execute or Open call.
Close	Closes a connection.
CommitTrans	Saves any changes and ends the current transaction. It can also be set to automatically start a new transaction.
Execute	Executes the query, SQL statement, stored procedure, or provider-specific text.
Open	Opens a physical connection to a data source.
OpenSchema	Returns descriptive schema information from the provider about the data source.
RollbackTrans	Cancels any changes that have occurred during the current transaction and then ends the transaction. It can also be set to automatically start a new transaction.

Collections

Errors	The Errors Collection contains all of the Error objects that were created as the result of a single failure involving the provider. Each time a failure occurs involving the provider, the Errors Collection is cleared and the new Error objects that have been created are inserted into the collection.
Properties	The Properties Collection is a collection of Property objects. Each Property object contains a single piece of information, called a dynamic property, about the database provider. By referring to the Properties Collection, each connection to a provider can be tailored specifically by ADO to suit the exact needs of that provider.

Events

BeginTransComplete	After a BeginTrans operation has finished executing,you can call this event to trigger other operations.
CommitTransComplete	After a CommitTrans operation has finished executing,you can call this event to trigger other operations.
ConnectComplete	After a connection has started, you can call this event to provide information on the success of the connection.
Disconnect	After a disconnection, you can call this event to provide information on the success of the disconnection.
ExecuteComplete	After a command has finished executing, you can call this event to provide information on the successof the command and the number of records affected.
InfoMessage	This event is called if a warning occurs during a ConnectionEvent operation.
RollbackTransComplete	After a RollbackTrans operation has finished executing,you can call this event to trigger other operations.
WillConnect	This event can be called before the connection starts.You can change any of the parameters and even cancel the connection.
WillExecute	This event is called before a pending command is executed.It allows you to change the execution parameters.