Err: '[DBNETLIB][ConnectionOpen (Invalid Instance()).]...'

Lourival · Post by **Lourival** » Wed 20 May 2009 13:46

I have an application wich cannot connect with a database using the version "4.45.0.15", but every thing works fine using version "4.20.0.6" of this driver. I just replace the DLL's to fix this, but I need the new version 'cause some bug fix of version 4.45.0.15 are necessary.
I'm using the driver within an application and an DLL compiled with Delphi 7. Only with Delphi 2007 compiled application this work fine, but when this application load a DLL and this DLL try to connect the following message raise, the same happen with Delphi 7 executable:

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Debugger Exception Notification
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Project FMaker.exe raised exception class EMSError with message '[DBNETLIB][ConnectionOpen (Invalid Instance()).]Conexão inválida.'.
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Break Continue Help
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There are some fixo to this?

Dimon · Post by **Dimon** » Thu 21 May 2009 14:06

Please check that the TSQLConnection.VendorLib property is set correctly.
If this will not solve the problem, please try to compose a small sample to demonstrate the problem and send it to dmitryg*devart*com.

pwerner · Post by **pwerner** » Mon 15 Jun 2009 13:57

Hello Dimon,

we encounter the same error like Lourival and at the moment we have no idea to solve that issue. Unfortunatley Lourival has not replied if your suggested solution had worked for him. But I can tell: it has not worked for us. But what is the situation?

We develop a software with Delphi 7 using your dbexpress drivers for MS SQL 2000 and 2005. On Windows Server 2003 everything was running well. Now one of our partners would like to use Windows Server 2008 - and here we encounter the error mentioned before by Lourival. We used the newest version (4.45.16) with FVendorLib := 'SQLOLEDB' which is according to the provided Readme.html correct, but all we get is that error message.

For the test we have used MS SQL Server 2005, listening to Port 1433. What I have seen with netstat is, that our software creates a lots of connections to port 1433, which stay open for a long time. But only an error is given back by the app. For a full overview here the code we use:

Code: Select all

  FDriverName := 'SQLServerConnection';
  FGetDriverFunc := 'getSQLDriverSQLServer';
  FLibraryName := 'dbexpsda.dll';
  FVendorLib := 'sqloledb.dll';
  FParams.Clear();
//  FParams.Add('DriverName=MSSQL');
  FParams.Add('HostName=' + FHost);
  FParams.Add('Database=' + FDatabase);
  FParams.Add('User_Name=' + FUserName);
  FParams.Add('Password=' + FPassword);
  FParams.Add('ErrorResourceFile=');
  FParams.Add('LocaleCode=0000');
  FParams.Add('BlobSize=-1');
  FParams.Add('MSSQL TransIsolation=ReadCommited');
  FParams.Add('OS Authentication=False');

Any ideas what else the problem could be?

Yours

Peter

Dimon · Post by **Dimon** » Mon 15 Jun 2009 15:13

Please try to install the SQL Server Native Client 2008 provider and check if the problem still exists.
Also you should set the TCRSQLConnection.VendorLib property to 'sqlncli'.

pwerner · Post by **pwerner** » Wed 17 Jun 2009 08:32

Hello Dimon,

we tried your recommendation and it is working. But what exactly is the difference now? I have found an article at the MSDN website for MS SQL Server 2008 what the SQL Native Client is but I have to admit that it is not fully clear to me if it makes a difference if we now use the native client in the future. For example what is the impact on the performance? O.K. we have made it configurable in our app which Vendor Lib should be used on a system. So I would like only understand what we are doing by changing the Vendor Lib. That's all. By the way: Thanks for your fast reply.

Peter

Dimon · Post by **Dimon** » Thu 18 Jun 2009 07:04

Changing of the VendorLib property allows to change a provider to access to a SQL server.
'sqlncli' uses SQL Native Client. It should be installed on the computer to use this Provider value. This provider offers maximum functionality set and more performance.
'sqloledb' uses the preinstalled with Windows provider which has limited functionality.
To use OLEDB provider for access to MS SQL Server 2008 make sure it supports this server.