Mysql not defined when compiling mysql driver

Thombou · wrote on 20 Apr 2020, 09:43

I have added the path to vcvarsall.bat in my path and I ran the command bcvarsall.bat amd64. After this, I have nmake in my path so that's ok.

I deleted the source component and I am making a fresh install now. I will start the compilation of the plugin after that.

Thombou · wrote on 20 Apr 2020, 10:52

Hi again,
So, Now i managed to do a proper installation of the plugin I guess. I now have in my C:\Qt\5.14.2\msvc2017_64\plugins\sqldrivers folder the qsqlmysql.dll and qsqlmysqld.dll.

I put the libmysql.dll in the same directory as my .exe file but I still have the same problem...

Here is part of the output

Cannot load library C:\Qt\5.14.2\msvc2017_64\plugins\sqldrivers\qsqlmysqld.dll: The specified module could not be found.
QLibraryPrivate::loadPlugin failed on "C:/Qt/5.14.2/msvc2017_64/plugins/sqldrivers/qsqlmysqld.dll" : "Cannot load library C:\Qt\5.14.2\msvc2017_64\plugins\sqldrivers\qsqlmysqld.dll: The specified module could not be found."

However in the directory it looks in I have the file:

MEMekaniske · wrote on 20 Apr 2020, 11:13

What if you now do as I have with my dlls, copy them to build where exe is in a folder sqldrivers.

If that won't work. There should be someone more competent on here that can help.
Everything seems fine to me regarding paths, versions etc.

Hope you manage to solve this :)

Thombou · wrote on 20 Apr 2020, 11:53

Same issue...
Can it be due to the compiler I use? As I mentioned I had to run the vcvarsall.bat file, where I have different options

I chose amd64 which is the same as the one I use to compile my qt projects.

MEMekaniske · 20 Apr 2020, 12:32

Everything seems to be right with compiler etc, because you get the ddls placed in the correct directories for the MSCV2017..
And since you use same architecture type on both builds there should be noe problem there either..

A quick fix for you is to use these:
https://github.com/thecodemonkey86/qt_mysql_driver/releases/tag/qmysql_5.14.2

But I suggest that you also check in on this thread to see if someone has answers leading to a permanent fix for future builds.
Or you can try the process again with mingw and see if that gives the same output etc, then at least you know if the environment for mscv is correct if the outputs are the same.

Thombou · 20 Apr 2020, 12:47

@MEMekaniske Thanks a lot! That works now.
It turns out that it is my libmysql.dll file that was not working.
I did different test and I figured out that if I just replace this file by the one provided in the link and keeping all other dll as I built them, it works.
I found my libmysql.dll file in the installation folder of my mysql server C:\Program Files\MySQL\MySQL Server 8.0. Any idea of what could be wrong about this one?

MEMekaniske · wrote on 20 Apr 2020, 12:45

That is good :)

Ok, only thing I can think of then is that the MySQL Server 8.0 installed is for a different architecture and cannot be used with amd64, maybe if you just download and install the versions that can be installed on your architecture and try with each of them to see if there is any difference.

If not, I guess it is a bug for the mysql community/support to take a look at

kshegunov · 20 Apr 2020, 14:11

@Thombou said in Mysql not defined when compiling mysql driver:

I did different test and I figured out that if I just replace this file by the one provided in the link and keeping all other dll as I built them, it works.

Did you check that the arch matches between the plugin and the client library? I'd hazard a guess that's what was wrong. Anyway, as you have it solved it wouldn't matter that much.

Thombou · 20 Apr 2020, 14:12

@kshegunov What do you call the client library? The libmysql.dll?

kshegunov · 20 Apr 2020, 14:22

@Thombou said in Mysql not defined when compiling mysql driver:

What do you call the client library? The libmysql.dll?

Yes!

Thombou · 20 Apr 2020, 14:31

@kshegunov I downloaded it from here https://dev.mysql.com/downloads/windows/installer/8.0.html.
As it is installed in the Program Files and not the Program Files (x86) directory I'd say it's 64bits...
Plus, this is what I installed so:

MEMekaniske · wrote on 20 Apr 2020, 14:31

@Thombou It says X64 under the architecture tab so should be the correct version.

MEMekaniske · wrote on 20 Apr 2020, 14:35

Also, if you go into the "Add" tab, then expand MySQL Servers, then expand MySQL Server, then choose MySQL Server 8.0 you get the option to choose the availiable architectures :)

Thombou · 20 Apr 2020, 16:03

Yes that's what I di not understand. it seems that I have the correct version but a wrong version of the libmysql.dll... Anyway, i hope that it is fixed now, and that I won't have other surprises like that later on.
Thank you very much for your help! It is much appreciated!

MEMekaniske · wrote on 20 Apr 2020, 16:03

@Thombou Yeah it is very frustrating.. hope all goes well with the next version!
Glad i could help :)

Thombou · 21 Apr 2020, 09:33

Shall I report a bug somewhere of shall I suppose the problem is on my side?

kshegunov · 21 Apr 2020, 13:50

@Thombou said in Mysql not defined when compiling mysql driver:

Shall I report a bug somewhere of shall I suppose the problem is on my side?

The latter. (And don't feel bad, it happens all the time, that's why this user forum exists)

Thombou · wrote on 21 Apr 2020, 13:50

@kshegunov Ok that's what I thought too :) haha. It's by doing that we learn!
Cheers :)

Thombou · 22 Apr 2020, 08:59

For those who are interested, I opened the 2 dlls with the dependancy walker. It turns out that the dll provided by mysqlserver required 2 additional dlls LIBSSL-1_1X64.DLL and LIBCRYPTO-1_1-x64.DLL which were not found. In the dll file that if working, those 2 additional dlls are not required. When placing those 2 DLLs in the folder of the executable everything works perfectly. This is the root cause of the problem.

MEMekaniske · wrote on 22 Apr 2020, 08:59

@Thombou very helpful information indeed! :)

What if you download those dlls to your exe lib and (there you did it already in the edit I see :p) hehe..

Very good, then you have complied the library successfully! Congratz :)