AddCommandDependency

This instance method binds the OracleDependency instance to the specified OracleCommand instance.

Declaration

// C#
Public void AddCommandDependency (OracleCommand cmd);

Parameters

cmd

The command that is to be bound to the OracleDependency object.

Exceptions

ArgumentNullException - The cmd parameter is null.

InvalidOperationException - The specified OracleCommand instance already contains a notification request.

Remarks

An OracleDependency instance can bind to multiple OracleCommand instances.

While it binds an existing OracleDependency instance to an OracleCommand instance, the AddCommandDependency method creates an OracleNotificationRequest instance, and sets it to the specified OracleCommand.Notification property.

When this method creates an OracleNotificationRequest instance, the following OracleNotificationRequest properties are set:

IsNotifiedOnce is set to the value True.
Timeout is set to 50,000 seconds.
IsPersistent is set to the value False, indicating that the invalidation message is stored in an in-memory queue before delivery.

With this method, multiple commands can be associated with a single Continuous Query Notification registration request. Furthermore, the OracleNotificationRequest attribute values assigned to the OracleCommand can be changed once the association between the OracleCommand and the OracleDependency is established.

However, when multiple OracleCommand objects are associated with a single OracleDependency object, the OracleNotificationRequest attributes (Timeout, IsPersistent, and IsNotifiedOnce) of the first executed OracleCommand object are used for registration, the attributes associated with subsequent OracleCommand executions will be ignored.

Furthermore, once a command associated with an OracleDependency is executed and registered, all other subsequent command executions and registration associated with the same OracleDependency must use a connection with the same "User Id" and "Data Source" connection string attribute value settings.

Otherwise, an exception will be thrown.