OraAQ Object

Description

An OraAQ object is instantiated by invoking the CreateAQ method of the OraDatabase interface. It represents a queue that is present in the database.

Remarks

Oracle Objects for OLE provides interfaces for accessing Oracle Database Advanced Queuing (AQ) feature. It makes AQ accessible from popular COM-based development environments such as Visual Basic.

The OraAQ Automation interface provides methods for enqueuing and dequeuing messages (encapsulated in the OraAQMsg object). It also provides a method for monitoring queues for message arrivals.

Client applications provide a Dispatch interface to the monitor. The monitor checks the queue for messages that meet the application criteria. It then invokes the NotifyMe method of the Dispatch interface when these messages are dequeued.

The following diagram illustrates the OO4O AQ Automation objects and their properties.

Description of the illustration o4o00016.gif

Properties

• Consumer (OraAQ) Property

• Correlate (OraAQ) Property

• DequeueMode (OraAQ) Property

• DequeueMsgId (OraAQ) Property

• Navigation (OraAQ) Property

• RelMsgId (OraAQ) Property

• Visible (OraAQ) Property

• Wait (OraAQ) Property

Methods

• AQMsg (OraAQ) Method

• Enqueue (OraAQ) Method

• Dequeue (OraAQ) Method

• MonitorStart (OraAQ) Method

• MonitorStop (OraAQ) Method

Examples

Example: Enqueuing Messages

Enqueuing messages of type RAW

"Enqueuing Messages of Type RAW"

Enqueuing messages of Oracle object types

"Enqueuing Messages of Oracle Object Types"

Example: Dequeuing messages

NOTE: The following code samples serve as models for dequeuing messages.

A complete AQ sample can be found in \OO4O\VB\SAMPLES\AQ

Dequeuing messages of the RAW type

"Example: Dequeuing Messages of RAW Type"

Dequeuing messages of Oracle object types

"Example: Dequeuing Messages of Oracle Object Types"

Example: Monitoring messages

See "Monitoring Messages" for examples illustrating the use of the MonitorStart and MonitorStop methods.