Does the Microsoft SQL Server native client support IDBAsynchNotify?

Question

I'm working on some OLE DB code that runs queries on MS SQL Server via ICommand::Execute. I'm converting this code to operate asynchronously by setting the DBPROPVAL_ASYNCH_INITIALIZE property on the command before executing.

I'd prefer to register a IDBAsynchNotify sink so that my code can be notified of events, as opposed to polling or blocking via ISSAsynchStatus.

The documentation for ICommand::Execute does not show IConnectionPointContainer as an acceptable riid parameter, but the same document, when discussing the DB_S_ASYNCHRONOUS return code, suggests that it is possible to request an IConnectionPointContainer interface that I could use to register my event sink.

When I call ICommand::Execute, passing IID_IConnectionPointContainer as the riid parameter, I receive the E_NOINTERFACE error. I also tried setting the DBPROP_IConnectionPointContainer property before Execute but I received the same results.

If I have to, I'll use ISSAsynchStatus, but I'd much rather use IDBAsynchNotify. Is it possible?

Answer 1

See Performing Asynchronous Operations for SQL Native Client OLE Db specifics, including examples. The link says the only acceptable RIIDs are IID_IDBAsynchStatus and IID_ISSAsynchStatus, so my understanding that is that the programming model is pool based, not notification based.

Answer 2

According to the response on this SQL Server Native Client blog post, "asynchronous notification programming model" was the fifth most important feature that was requested for the native client. I guess that answers the question. Hopefully the sqlncli team will address this sooner rather than later. I am easily annoyed by polling.