Samuel - 

Please tell us more about how your multi-threaded application manages the PB Transaction object(s).

Does each thread create/connect/destroy its own Transaction object, or is it using/reusing SQLCA?

If it's using SQLCA, please be aware that each thread uses it own, local copy of global objects (like SQLCA). Syntactically, there is no problem doing this, but threads work with global objects a little differently than what you are probably used to.

Threads cannot share a database connection, nor can they access the global objects in use by either the main (GUI) thread or by any other thread. PB gives each thread a copy of global objects and variables as if the application has just initialized and started execution. This is done for thread safety. Therefore, the SQLCA your app uses in the main/GUI thread is NOT the same SQLCA used in alternate execution threads.

I've written an article in the PowerBuilder section about multi-threading in PB that explains this (and other aspects of multi-threaded PB applications) you may find helpful:

   https://community.appeon.com/index.php/articles-blogs/tutorials-articles/2-powerbuilder/339-free-my-gui-multi-threading-in-powerbuilder

There is also an accompanying sample application in CodeXchange that shows one possible technique for retrieving data from a database with multi-threading.

   https://community.appeon.com/index.php/codeexchange/powerbuilder/307-a-multi-threaded-data-retrieval-example

Best regards, John

I don't know why this happens. You could try to use Process Monitor (by Sysinternals) to see how PowerBuilder is looking for the DLL in singlethreaded and multithreaded application.

Do you have your runtime folder in PATH variable or do you use the XML file to specify the runtime path. Maybe that is somthing wrong with PB if you use XML file (maybe if working directory is not the application directory?). If you use XML try to add the runtime folder to PATH to see if this works.

You should open a support ticket about this.

This is probably NOT directly related to your issue, but the Adaptive Server Enterprise (ASE) database interface (SQLCA.DBMS="ASE") intended for use with Sybase ASE v15 and newer made it's debut in PB 11.0, in 2007. You did not state which version of ASE you are using, but you might wish to consider switching away from using an interface (SYC) that pre-dates PB 11.

Only the first three characters of SQLCA.DBMS are used. Those three characters are used to build the name of the DB interface dll. Something like this:

ls_dllname = "PB" + Left(SQLCA.DBMS, 3) + ".DLL"

The error message you are seeing is caused by the DLL not being found. Make sure PBSYC.DLL is included in the PB runtime folder and that Sybase Open Client is properly configured.

Hi Samuel;

  This error can normally be caused by two things ...

1. You did not install the SNC Drivers from Microsoft for SS.
2. You did not deploy the PBSYC.dll DB client "interface" driver (part of the PB runtime).

HTH

Regards ... Chris