plugin vs driver

[L.Marvell]

Please explain me the difference between the -qt-sql-mysql and -plugin-sql-mysql for example.

Oops... Found in FAQ:
Pass option "-qt-sql-mysql" to configure – this will compile MySQL support directly into Qt.

Pass option "-plugin-sql-mysql" to configure – this will compile MySQL support as plugin.

But. I've build Qt staticaly with -qt-sql-mysql. Then compiled my app that works with MySQL, but it said it cannot find libmysql.dll. But it has to be "compiled directly into Qt", hasn't it?

[wysota]

But it has to be "compiled directly into Qt", hasn't it?

No, libmysql.dll is a client library bundled with MySQL, it won't be compiled statically into the driver, at least not unless you have a static version of libmysql client library installed on your system. It is not a part of the plugin.

[L.Marvell]

No, libmysql.dll is a client library bundled with MySQL, it won't be compiled statically into the driver, at least not unless you have a static version of libmysql client library installed on your system. It is not a part of the plugin.

So all the difference is if I compile plugin (-plugin-sql-mysql) I need to share it with my app, if I compile driver (-qt-sql-mysql) I need to share libmysql.dll with my app?

[jacek]

So all the difference is if I compile plugin (-plugin-sql-mysql) I need to share it with my app, if I compile driver (-qt-sql-mysql) I need to share libmysql.dll with my app?

No, with -plugin-sql-mysql you will have to deliver the plugin and libmysql.dll, and with -qt-sql-mysql only libmysql.dll (because the plugin will be "hidden" inside Qt).

[L.Marvell]

And one more question. I've build qt also with -qt-sql-pgsql option and now my appliaction need libpq.dll to start, but I it doesn't use it, only libmysql.dll. How can I get rid of this dependency?

[jacek]

How can I get rid of this dependency?

Don't use -qt-sql-pgsql.

[L.Marvell]

Don't use -qt-sql-pgsql.

Does it mean I need to rebuild Qt again but without this option? Can I build only app without this dependency?

[jacek]

Does it mean I need to rebuild Qt again but without this option? Can I build only app without this dependency?

Yes, you will have to rebuilt Qt, because Qt depends on that DLL, not your application. If you were using plugins you wouldn't have to (in Qt4 you can use "static" plugins that you can compile into your application).

[L.Marvell]

Greate thanks for explanations!