MySQL Driver not loaded on PC without Qt

[KTvsPeacock]

i'm using the qt sdk and i took the dll from the qt/bin-folder (except the qsqlmysql4.dll of course).

doesn't QApplication only looks in the given library paths for plugins?
normally it searches in qt/plugins/ and the app-folder. i removed both using setLibraryPath(""), but still the qsqlmysql4.dll in qt/plugins was found and used. this is confusing

[wysota]

The plugin has to reside in a sqldrivers subdirectory of the directory containing the binary of your application.

[KTvsPeacock]

you mean like this:

"2nd try:

/App/app.exe
.
.
.
/App/sqldrivers/qsqlmysql4.dll"

i already tried this :/

[wysota]

Maybe you were missing something else too, like the MySQL client library.

[KTvsPeacock]

Isn't this the libmysql.dll?
It's in the /App-folder. If I try to put it somewhere else, the application won't start.
Somewhere has to be an entry that tells something like "look only in qt/plugins for plugins no matter what you're supposed to do".

[wysota]

It's in the /App-folder. If I try to put it somewhere else, the application won't start.

It should start. Your main application shouldn't depend on the mysql client library. What does dependency walker say?

[KTvsPeacock]

You were right: it starts without libmysql.dll.
It depends on kernel32, mingwm10, msvcrt, libgcc_s_dw2-1, qtcore4, qtgui4, qtsql4, and qtwebkit4.dll

///
This is what I get, when I call the libraryPaths()-method of my application:
("D:/Programme/Qt/qt/plugins", "C:/Release/nV/release")
So I removed the first path calling removeLibraryPath("D:/Programme/Qt/qt/plugins").
Called librayPath() again, got only the second path and still the application took the dll from the removed path.

[wysota]

But what exactly is the problem with the first path being there?

[KTvsPeacock]

The problem is that my Application only searches in that path, no matter what, for plugins.
I could add thousand additional paths and put the needed dll in every single one of them, but only the one lies in the qt/plugins-path will be used.
And this is not that good, if I want to use my application on a PC without Qt :/

[wysota]

The problem is that my Application only searches in that path, no matter what, for plugins.

How do you know it doesn't search elsewhere?

I could add thousand additional paths and put the needed dll in every single one of them, but only the one lies in the qt/plugins-path will be used.
And this is not that good, if I want to use my application on a PC without Qt :/

Apparently you are missing some library that is required by the driver. Run dependency walker on the plugin and see if anything is missing and what is required for it to work.

[KTvsPeacock]

It was just a guess, because by removing every library path the application will still look in qt/plugins/sqldrivers.

I used Dependency Walker on App/sqldrivers/qsqlmysql4.dll:
QtCore4.dll and QtSql4.dll were missing, but they were in the /App-folder, so I copied them also into that folder.
-> Available Drivers: ("QSQLITE", "QMYSQL3", "QMYSQL", "QODBC3", "QODBC") , but still QSqlError(-1, "Driver not loaded", "Driver not loaded")

Dependencies on qsqlmysql4.dll:
LIBMYSQL.DLL
KERNEL32.DLL
MINGWM10.DLL
MSVCRT.DLL
LIBGCC_S_DW2-1.DLL
QTCORE4.DLL
QTSQL4.DLL

[wysota]

Obviously your driver is seen by the application. Show us your code.