How to add a lib to a qt project

[WilliamSpiderWeb]

Hey Chris,
thanks for helping me again.

I followed your detailed instructions.
The differences to my last try is, this time I used "Qt command prompt". Last time it was "Windows command prompt". And there was a blank in the installation path of postgresql. I elliminated the blank for plugin building now.

There were no error messages while building the plugin now.

But I haven't understood what to do now to use the plugin.

[WilliamSpiderWeb]

Okay,
Here in Qt Centre I found this wiki article:
http://www.qtcentre.org/wiki/index.p...ws_using_MinGW

When I compare what I've done with this article, I find the files "qsqlpsql4.dll" and "qsqlpsqld4.dll" in the folder "%QTDIR%\plugins\sqldrivers".

If I load the "qsqlpsql4.dll" with the dependency walker I get the information that there are a few files missing (libpq.dll, mingwm10.dll, libgcc_s_dw2-1.dll, qtcore4.dll, qtsql4.dll).

Tomorrow I'll try to update my enviromental variable paths.
Please tell me if I'm completly wrong.

Greetings

[wysota]

Lot to learn you still have, young padawan. However on the right path you are.

[ChrisW67]

Okay,
If I load the "qsqlpsql4.dll" with the dependency walker I get the information that there are a few files missing (libpq.dll, mingwm10.dll, libgcc_s_dw2-1.dll, qtcore4.dll, qtsql4.dll).

When you started Dependency Walker it was given the default Windows environment PATH, which does not include the Qt bin directories that contain all of the Qt and MingW files listed there. The default environment PATH also does not contain the PostgreSQL binary directory for the PostgreSQL library. Consequently, the Dependency Walker could not load any of these DLLs. If you had launched the Dependency Walker from the "Qt Command Prompt" most of the libraries, except the Postgres ones, would have been found.

You should add the PostgreSQL bin directory to your system PATH. If you develop your program in an environment with the Qt paths set properly such as the Qt Command Prompt or Qt Creator then you should not need to add QT or MingW stuff to the system path. When you deploy you will need to ship the MingW, PostgreSQL and Qt libraries with your application.

[WilliamSpiderWeb]

Now I added the following paths to the enviroment variable path

C:\psql9\bin
C:\qt\2010.05\bin
C:\qt\2010.05\qt\bin
C:\qt\2010.05\mingw\bin

But then there are more and more dlls the dependency walker cannot found or with other errors

Error: At least one module has an unresolved import due to a missing export function in an implicitly dependent module.
Error: Modules with different CPU types were found.

[WilliamSpiderWeb]

Just to inform other Newbies who want to connect to PostgreSQL databases as well...

My last-ditch attempt was, just don't care about what the results of the dependency walker are and copied ALL dlls of %postgresdir%\bin.

Now I can load the QPSQL Driver and connect to my postgresql database.

At this point I want to thank the experts of this forum again for trying to help me.


Greetz, wsw