Why QOCI plugin isn't working

Question

I am trying to use Qt with QOCI (actually, along with other plugins as well) but for some reason I cannot. Here is what I did and result:

1- http://doc.qt.nokia.com/latest/sql-driver.html#qoci plug-in is built successfully.

2- copied the plugin debug & release dll and lib files to plugins/sqldrivers and OCI.DLL to %WINDIR%\system32 (plugins/sqldrivers is where other plugins such as QPSQL and QMYSQL are)

3- QSqlDatabase::isDriverAvailable(QOCI) returns false where it returns true for QMYSQL and QPSQL. I did the same for QMYSQL and QPSQL

4- QStringList qsl = QSqlDatabase::drivers(); There is no QOCI in the string list returned. however there is QMYSQL, QPSQL and some others.

additional checks: opened qsqloci4.dll with dependency walker, 3 dlls were impossible to locate: 1-QtCore4.dll 2-QtSql4.dll 3-MSVSC80.dll However it is also impossible to locate them when opening qsqlpsql.dll with dependency walker. I believe that loading dll did not fail because of dependencies of qsqloci4.dll. But still, any ideas are welcomed.

NEWS

LoadLibrary(_T("C:\\QtSDK\\Desktop\\Qt\\4.7.3\\msvc2005\\plugins\\sqldrivers\\qsqloci4.dll");

and

LoadLibrary(_T("C:\\QtSDK\\Desktop\\Qt\\4.7.3\\msvc2005\\plugins\\sqldrivers\\qsqlocid4.dll");

fails!!! Please not that both of those files exist in the given path.

I believe that Qt also cannot load the plugin due to this error. Now question is a bit different but, why does LoadLibrary fail in this case? Any ideas?

Thanks in advance.

Answer 1

How to Build the Plugin on Windows

Choosing the option "Programmer" in the Oracle Client Installer from the Oracle Client Installation CD is sufficient to build the plugin.

Build the plugin as follows (here it is assumed that Oracle Client is installed in C:\oracle):

set INCLUDE=%INCLUDE%;c:\oracle\oci\include
set LIB=%LIB%;c:\oracle\oci\lib\msvc
cd %QTDIR%\src\plugins\sqldrivers\oci
qmake -o Makefile oci.pro
nmake

If you are not using a Microsoft compiler, replace nmake with make in the line above.

When you run your application you will also need to add the oci.dll path to your PATH environment variable:

set PATH=%PATH%;c:\oracle\bin

Answer 2

You need to create a folder call sqldrivers in the directory containing your exe. Put all the SQL driver DLLs you are using in there (for oracle oci.dll, ociw32.dll, oraociei12.dll, oraons.dll, qsqloci4.dll, qsqlocid4.dll).