ODBC Connection in a Windows service
lazarus / 16-Databases

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relocate · 2021-09-21 06:44

I want to connect to an MSSQL Server via a service in Windows.
But it won't connect.
In a standard program everything works as it should, but not in the
service.
The suggested solution to create a system DNS doesn't help.
The handles are created, only when it comes to the Connection it goes
wrong.
I dont't use Lazarus only pure Free Pascal and the odbcsqldyn unit.

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ccrause · 2021-09-21 08:24

Just thinking out loud - could this be a privilege issue because the
service doesn't run within a user context? Can you retrieve an error
code, this could help in identifying the problem.

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Zvoni · 2021-09-21 08:27

1) is your service dependent on the Database-Service? As in: Is the
DB-Service up and running, before your Service starts?
2) Have you tried within your service to Login with your Windows-user-
Account?
https://www.codeproject.com/Questions/185651/ODBC-through-Windows-
Service-Win-7-x64

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relocate · 2021-09-21 09:27

@ccrause
I only get -1 as errorcode. That's the returncode from SQLConnect, I
don't know if i can get any other code.

@zvoni
1) No, the Database is located on an server which is allready running,
so no dependences.
2) Yes, I allready tried it. But you brought me onto the right course,
I took the wrong user. (local instead of domain user), it works, thank
you!

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Zvoni · 2021-09-21 10:11

Ah, yes.
Domain-User makes more sense, if the DB-Server is on another machine
of the Network

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relocate · 2021-09-21 10:28

Yes, I thought I'd took the right user, but NO.

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paweld · 2021-09-21 10:52

try initialize multithreading for the COM objects:
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i uses 
ComObj; begin  CoInitializeEx(nil, COINIT_MULTITHREADED); 
SQLConnection1.Connect;  //queries  SQLConnection1.Disconnect; 
CoUnInitialize; end;

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Zvoni · 2021-09-21 12:40

Pawel
what's that got to do with the initial problem?
The OP has a Network-Service which wasn't running under a User-Context
trying to access a network-ressource which is bound to fail

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relocate · 2021-09-21 13:10

@paweld
according to zvoni I would ask the same, on which circumstances I
should use this for the problem.
Or did the answer just go to the wrong question?

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paweld · 2021-09-21 15:16

Admittedly I am not using ODBC but SDAC components, but with windows
service the component does not want to connect to MSSQL until
multithreading is initiated for COM objects.

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relocate · 2021-09-22 07:04

Thanks for the clarification, I don't know if there is a correlation,
but with the solution through the windows service it works. And it
seems to be a valued solution because in some cases services need user
rights to forefill their tasks.