QSqlDatabase: QMYSQL driver not loaded available drivers: QMYSQL

fennec · wrote on 14 Apr 2015, 23:42

I am trying to connect to a MySQL database.
It is currently give me this error:

QSqlDatabase: QMYSQL driver not loaded
QSqlDatabase: available drivers: QSQLITE QMYSQL QMYSQL3 QODBC QODBC3 QPSQL QPSQL7

I have used: #include <QtSql> at the top. I have added QT += sql in the pro file.
I have MySQL installed. I have the libmysql.dll in the same folder as my .exe.
I have qsqlmysql.dll and qsqlmysqld.dll in /plugins/sqldrivers and also in a folder called sqldrivers where the .exe exists.
I have made the qsqlmysql.dll and qsqlmysqld.dll files myself.

I have ran out of ideas why is can not load but is available.

SGaist · 15 Apr 2015, 10:13

Hi and welcome to devnet,

Do you also have the MySQL client libraries installed on your computer ?

mcosta · wrote on 15 Apr 2015, 06:10

Hi,

please guys, before create a new thread use the SEARCH tool in this forum.
I (and probably a lot of guys like @SGaist) answered at least to 4/5 threads with exactly the same question in this week

fennec · 15 Apr 2015, 10:39

@SGaist I have the Connector/C++ installed, I also have MySQL Server, MySQL Workbench and MySQL for Visual Studio installed.

p3c0 · 15 Apr 2015, 12:08

@fennec Use dependencywalker to find out which dll's are missing. Check for qsqlmysql dll.

fennec · P p3c0 15 Apr 2015, 10:39

@p3c0 I used the dependenctwalker as these are the missing .dll's but its not anything to do with mysql

API-MS-WIN-APPMODEL-RUNTIME-L1-1-0.DLL
API-MS-WIN-CORE-WINRT-ERROR-L1-1-0.DLL
API-MS-WIN-CORE-WINRT-L1-1-0.DLL
API-MS-WIN-CORE-WINRT-ROBUFFER-L1-1-0.DLL
API-MS-WIN-CORE-WINRT-STRING-L1-1-0.DLL
API-MS-WIN-SHCORE-SCALING-L1-1-1.DLL
DCOMP.DLL
IESHIMS.DLL

I used Profiling and when I click the button that calls the mysql to connect i get this:

Loaded "QSQLMYSQLD.DLL" at address 0x000000006AD80000.  Successfully hooked module.
Unloaded "QSQLMYSQLD.DLL" at address 0x000000006AD80000.
LoadLibraryW("E:\Qt\5.4\msvc2013_64\plugins\sqldrivers\qsqlmysqld.dll") returned NULL. Error: %1 is not a valid Win32 application (193).
QSqlDatabase: QMYSQL driver not loaded
QSqlDatabase: available drivers: QSQLITE QMYSQL QMYSQL3 QODBC QODBC3 QPSQL QPSQL7

I have qsqlmysqld.dll in that folder.

mcosta · 15 Apr 2015, 18:13

Hi,

is the mysqlclient.dll in your PATH??

Which compiler/kit are you using?

May help?? https://forum.qt.io/topic/53247/solved-qtsql-and-xampp-mysql-qmysqldriver-not-loaded/6

fennec · M mcosta 15 Apr 2015, 17:39

@mcosta I have now added the lib of XMAPP and MYSQL server to path and Path still the same problem.
I am currently using: Desktop QT 5.4.1 MSVC2013 64bit
My other option is: Desktop QT 5.4.1 MSVC2010 OpenGL 32bit, but this give the error: LNK1104: cannot open file 'libmysql.lib'

mcosta · 15 Apr 2015, 19:35

Just to be sure:

In which directory is the mysqlclient library?
can you post the %PATH% contents?

fennec · M mcosta 15 Apr 2015, 18:16

@mcosta the mysqlclient lib is in: C:\Program Files\MySQL\MySQL Server 5.6\lib

This is User Variables:

C:\Program Files\MySQL\MySQL Server 5.6\lib
E:\Qt\5.4\mingw491_32\plugins\sqldrivers
C:\WINDOWS\
E:\Python27
%CommonProgramFiles%\Microsoft Shared\Windows Live
E:\xampp\mysql\lib

This is System Variables:

C:\Program Files\MySQL\MySQL Server 5.6\lib
E:\xampp\mysql\lib
C:\ProgramData\Oracle\Java\javapath
E:\Program Files\Microsoft Solver Foundation\3.0.2.10889\Plugins
C:\Program Files (x86)\NVIDIA Corporation\PhysX\Common
%CommonProgramFiles%\Microsoft Shared\Windows Live
C:\Program Files (x86)\Intel\iCLS Client\
C:\Program Files\Intel\iCLS Client\
C:\Windows\system32
C:\Windows
C:\Windows\System32\Wbem
C:\Windows\System32\WindowsPowerShell\v1.0\
C:\Program Files\Intel\Intel(R) Management Engine Components\DAL
C:\Program Files\Intel\Intel(R) Management Engine Components\IPT
C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\DAL
C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\IPT
C:\Program Files (x86)\Microsoft SQL Server\100\Tools\Binn\
C:\Program Files\Microsoft SQL Server\100\Tools\Binn\
C:\Program Files\Microsoft SQL Server\100\DTS\Binn\
C:\Program Files\TortoiseSVN\bin
C:\Program Files\Microsoft SQL Server\110\Tools\Binn\
C:\Program Files (x86)\Microsoft SDKs\TypeScript\1.0\
C:\Program Files\Microsoft SQL Server\120\Tools\Binn\
E:\xampp\php
C:\ProgramData\ComposerSetup\bin
C:\Program Files (x86)\Skype\Phone\
C:\Program Files\MySQL\MySQL Server 5.6\lib
E:\Qt\5.4\mingw491_32\plugins\sqldrivers

mcosta · 15 Apr 2015, 22:35

Hi,

do you have mysql both in C:\Program Files\MySQL\MySQL Server 5.6\lib and E:\xampp\mysql\lib ??

Which version of MySQL do you used to build the Qt driver?
Keep in mind that the MinGW version of Qt is built in 32bit so you cannot load 64bit libraries

fennec · M mcosta 15 Apr 2015, 20:08

@mcosta I have libmysql.lib in both folders

I used the mysql 5.6.24 server to make the files which is the latest version.

Since I cant use the 32bit driver for the 64bit. [ill look into making the 64bit later]

the 32bit version i cannnot build as it give the error: LNK1104: cannot open file 'libmysql.lib'

I used 'Add Library...' to add libmysql.lib and is put this in the .pro file

win32:CONFIG(release, debug|release): LIBS += -L$$PWD/C:/Program Files/MySQL/MySQL Server 5.6/lib/ -llibmysql
else:win32:CONFIG(debug, debug|release): LIBS += -L$$PWD/C:/Program Files/MySQL/MySQL Server 5.6/lib/ -llibmysqld
else:unix: LIBS += -L$$PWD/C:/Program Files/MySQL/MySQL Server 5.6/lib/ -llibmysql

INCLUDEPATH += $$PWD/C:/Program Files/MySQL/MySQL Server 5.6/include
DEPENDPATH += $$PWD/C:/Program Files/MySQL/MySQL Server 5.6/include

but still give the same error.

SGaist · 17 Apr 2015, 17:08

It should be -lmysql

mcosta · wrote on 15 Apr 2015, 23:11

IIRC (sorry now I'm on Mac) in Windows you need to quote paths if they contain spaces.

mcosta · wrote on 15 Apr 2015, 23:18

Have you built the Qt driver?? what is the MySQL version used for it??

IIRC the standard version of MySQL per Windows is built with Visual C++ (I think 64bit); so you cannot link it to a Mingw32 version of Qt

fennec · S SGaist 15 Apr 2015, 22:41

@SGaist -lmysql didnt help sorry.
@mcosta I built the driver myself, using the mysql server 5.6 to build the program 32bit
currently im making a vmware station of linux and win7 clean installs and install qt and mysql on that and try it out.
though i have been busy the last couple of days this may take some time.

SGaist · wrote on 17 Apr 2015, 20:12

One thing's not clear, are you trying to build the plugin against the embedded MySQL server ?

mcosta · wrote on 17 Apr 2015, 20:16

@fennec As I said in a previous post you should check that the MySQL version you're using to build the Qt Driver is in 32bit because you're using a 32bit Qt version.

And really I don't understand why you have two different version of MySQL installed on your machine

fennec · wrote on 23 Apr 2015, 23:25

I have made a VM of windows 7 and it works. so something is wrong with my pc but works on a clean win7.

EXTREME · wrote on 28 Dec 2016, 22:25

Hello everybody!
Firstly I'm sorry for resurrecting the thread, but my question is the same of the OP and I don't want to create a new one topic for the same problem.

Let me state what's happening with me:
I have Qt 5.7 and also MySQL 5.5 installed on my PC, I'm using mysql database on my program and it works... I do everything with it, read and write on database. No problem here.

When I deploy the app using the 'windeployqt' it generates all the dlls needed to the program run BUT the database don't connects and I get the error "Driver not loaded"... Crazy..

The mysql server is running and accessible for external connections. I'm connected on it by MySQL Workbench, so.. it's not about the access, its the driver...

I really don't understand how it works on my PC and the deploied program doesn't.

Please help me!