🚀 go-pugleaf

> As you say, there is unfortunately in ADO/OLEDB no way to determine the
> level of transaction support prior to calling a transaction. This is very
> poor design.
This subjective opinion
OLEDB technology - very extensibled.
If such property not exists, this does not signify that its it is impossible
add.

> Also it appears that there is no way to support overlapped
> transactions as opposed to either single transactions or nested
transactions
> in ADO/OLEDB. Some databases, such as Interbase, support overlapped
> transactions and not nested transactions.

Yes, InterBase connection can have multiple overlapped transactions
http://www.ibprovider.com/eng/examples/example_09_02.html

Once again:
 - Support of overlapped transactions - "Active Sessions" >1 (or ==0).
 - Property with information about support nested transaction not exists.

> If I call
> TADOConnection::BeginTrans() using Interbase and a transaction already
> exists in the connection, does BeginTrans() fail and throw an exception or
> does it succeed and return a value of 1 indicating a top-level transaction
?

In this case, InterBase OLEDB provider must be throw exception with error
code ....

Apropos, current status of transaction (session object) you can receive
througn ITransaction::GetTransactionStatus

> All in all, MS's documentation on transaction level support is very poor.
Yes, yes, certainly. Full shit. Reading the comics is much more interesting.

--
Bye
Dmitry Kovalenko
http://www.ibprovider.com