FreeTDS Development Group

["Bill Thompson" <thompbil AT exchange.uk.ml.com>]

Hi all,

I have an explanation for the "output parameters" issue.

In TDS 4.2, there was no direct method or protocol for submitting remote
procedure calls to the server. the only way to do it was via an "exec"
statement sent as an ordinary piece of SQL. In TDS 4.2, if a stored
procedure call with output parameters was submitted in this way, then a
token stream was returned, indicating the vales of the output parameters.

In TDS 7.0, Microsoft introduced a message type for directly submitting
remote procedure calls to the server. If this is used, then the token
stream will be returned.

However, up until SQL server 7 service pack 3, SQL server continued to
send back the "return value" token streams under the old conditions. In
7.0 SP3 MS put this behaviour under a TDS version check - old drivers got
the returnvalue, new ones did not.

The upshot of this is that we'll have to implement the RPC message stream,
if we want to capture return parameters from stored procedures in TDS 7 or
8.

I can help with the specifics of the TDS 7 RPC message protocol if anyone
wants to get stuck in.

Bill