Qt5.11.2, QSqlDatabase, QMYSQL, Driver not loaded

SPlatten

@SGaist , can you guide me please I'm not sure how to do that.

SGaist

It's shown the Qt Creator documentation.

SPlatten

@SGaist , I'm struggling with the documentation, the version of Qt Creator I'm using is:

Qt Creator 4.7.0-rc1 (4.6.84)

From the link posted I don't see, Projects > Build & Run > Run

How do I get to this section?

[Edit], found it, I'm so blind, I was looking for a menu option, it was right in front of me on the left vertical tool bar.

SPlatten

@SPlatten said in Qt5.11.2, QSqlDatabase, QMYSQL, Driver not loaded:

QT_DEBUG_PLUGINS

@SGaist , this is the output when the QT_DEBUG_PLUGINS is correctly added, I think I've isolated the problem, but not sure why its looking for this file and it doesn't exist::

2018-10-10 10:30:42.060973+0100 SimonQtWidgets[2001:286805] Got keys from plugin meta data ("QPSQL7", "QPSQL")
2018-10-10 10:30:42.060985+0100 SimonQtWidgets[2001:286805] QFactoryLoader::QFactoryLoader() checking directory path "/Users/simonplatten/build-SimonQtWidgets-Desktop_Qt_5_11_2_clang_64bit-Debug/SimonQtWidgets.app/Contents/MacOS/sqldrivers" ...
2018-10-10 10:30:42.063252+0100 SimonQtWidgets[2001:286805] Cannot load library /Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib: (dlopen(/Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib, 133): Library not loaded: /usr/local/mysql/lib/libmysqlclient.20.dylib
  Referenced from: /Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib
  Reason: image not found)
2018-10-10 10:30:42.063276+0100 SimonQtWidgets[2001:286805] QLibraryPrivate::loadPlugin failed on "/Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib" : "Cannot load library /Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib: (dlopen(/Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib, 133): Library not loaded: /usr/local/mysql/lib/libmysqlclient.20.dylib\n  Referenced from: /Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib\n  Reason: image not found)"
2018-10-10 10:30:42.0
63293+0100 SimonQtWidgets[2001:286805] QSqlDatabase: QMYSQL driver not loaded
2018-10-10 10:30:42.063465+0100 SimonQtWidgets[2001:286805] QSqlDatabase: available drivers: QSQLITE QMYSQL QMYSQL3 QPSQL QPSQL7

The file it appears to be looking for which doesn't exist:

    /usr/local/mysql/lib/libmysqlclient.20.dylib

There is no mysql folder in /usr/local/

I just ran:

    find / -name mysql

It returned:

    /usr/local/bin/mysql

There are also:

/usr/local/Cellar/mariadb/10.1.17/bin/mysql
/usr/local/Cellar/mariadb/10.1.17/include/mysql
/usr/local/Cellar/mariadb/10.1.17/share/mysql
/usr/local/Cellar/mariadb/10.2.6/bin/mysql
/usr/local/Cellar/mariadb/10.2.6/include/mysql
/usr/local/Cellar/mariadb/10.2.6/include/mysql/mysql
/usr/local/Cellar/mariadb/10.2.6/.bottle/etc/init.d/mysql
/usr/local/Cellar/mariadb/10.2.6/.bottle/etc/logrotate.d/mysql
/usr/local/Cellar/mariadb/10.2.6/share/mysql

I also found this in share:

lrwxr-xr-x    1 simonplatten  admin     36 10 Jun  2017 mysql -> ../Cellar/mariadb/10.2.6/share/mysql

Sunfluxgames

Please make sure you complie the Qmysql plugin in qtbase folder

Link x86 libs or x64 libs with whatever mysql you have installed on your system.

Copy sqldriver folder to complier folder

Should fix all sql drivers not finding the correct path locations.

Also make sure you override the static qmysql plugins as there are static ones that come shipping with it.

SPlatten

@Sunfluxgames , I copied:

libqsqlmysql.dylib

to:

~/build-SimonQtWidgets-Desktop_Qt_5_11_2_clang_64bit-Debug

The problem and reported errors haven't changed, still the same.

JonB

@SPlatten
I do not use Mac or compile Qt.

But it seems to me that the error message:

Cannot load library /Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib: (dlopen(/Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib, 133): Library not loaded: /usr/local/mysql/lib/libmysqlclient.20.dylib

is unequivocal. You need a libmysqlclient.20.dylib. (Moving just libqsqlmysql.dylib to somewhere is not going to address this.)

Try Googling for libqsqlmysql. There are others asking about this being missing under Linux/MacOS. You may need to download it (apt-get under MacOS? I have no idea) given what you show from your find and/or see e.g. https://afshinm.name/2016/02/05/how-to-fix-library-not-loaded-libmysqlclient-18-dylib-in-mac-os-x/

Sunfluxgames

~/Qt/5.11.2/clang_64/bin/qmake "INCLUDEPATH += /usr/local/mysql/include/" "LIBS += -L/usr/local/mysql/" mysql.pro

Complie mysql.pro in qtbase/sqldrivers

And then:

cp ~/Qt/5.11.2/Src/qtbase/plugins/sqldrivers/ ~/Qt/5.11.2/clang_64/plugins/sqldrivers/

Also might need to copy them to the creator folder as well to debug inside creator.

SPlatten

@Sunfluxgames , there i no /usr/local/mysql folder on my system, its MariaDB, when I ran:

    ~./Qt/5.11.2/clang_64/bin/qmake "INCLUDEPATH += /usr/local/mysql/include/" "LIBS += -L/usr/local/mysql/" mysql.pro

I got:

    Cannot find file: mysql.pro.

SGaist

Before trying to build anything (you need to first download the sources for that). Please run your application with the QT_DEBUG_PLUGINS environment variable set to 1.

Click on the Project button on the vertical toolbar on the left of Qt Creator, and there you'll find the Build and Run settings. Modify the Environment in the Run settings.

SPlatten

@SGaist , I did that, hasn't helped.

SGaist

It's not supposed to change anything in the application execution. The goal is to provide you with additional information about what is happening when plugins are getting or not loaded and from there help find what might be going wrong.

SPlatten

@SGaist said in Qt5.11.2, QSqlDatabase, QMYSQL, Driver not loaded:

QT_DEBUG_PLUGINS

With QT_DEBUG_PLUGINS added to the environment the output when single stepping over:

    QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL");

Is:

2018-10-11 08:28:13.253913+0100 SimonQtWidgets[1031:41669] Got keys from plugin meta data ("QPSQL7", "QPSQL")
2018-10-11 08:28:13.253927+0100 SimonQtWidgets[1031:41669] QFactoryLoader::QFactoryLoader() checking directory path "/Users/simonplatten/build-SimonQtWidgets-Desktop_Qt_5_11_2_clang_64bit-Debug/SimonQtWidgets.app/Contents/MacOS/sqldrivers" ...
2018-10-11 08:28:13.255823+0100 SimonQtWidgets[1031:41669] Cannot load library /Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib: (dlopen(/Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib, 133): Library not loaded: /usr/local/mysql/lib/libmysqlclient.20.dylib
  Referenced from: /Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib
  Reason: image not found)
2018-10-11 08:28:13.255844+0100 SimonQtWidgets[1031:41669] QLibraryPrivate::loadPlugin failed on "/Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib" : "Cannot load library /Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib: (dlopen(/Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib, 133): Library not loaded: /usr/local/mysql/lib/libmysqlclient.20.dylib\n  Referenced from: /Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib\n  Reason: image not found)"
2018-10-11 08:28:13.255
859+0100 SimonQtWidgets[1031:41669] QSqlDatabase: QMYSQL driver not loaded
2018-10-11 08:28:13.255885+0100 SimonQtWidgets[1031:41669] QSqlDatabase: available drivers: QSQLITE QMYSQL QMYSQL3 QPSQL QPSQL7

jsulm

@SPlatten said in Qt5.11.2, QSqlDatabase, QMYSQL, Driver not loaded:

Library not loaded: /usr/local/mysql/lib/libmysqlclient.20.dylib

Do you have this lib in that location?

SPlatten

@jsulm , No, I've no idea what this library is or where is comes from. The path /usr/local/mysql doesn't exist.

jsulm

@SPlatten This is the MySQL client library which is used by Qt to access MySQL databases. You need it if you want to use MySQL.

SPlatten

@jsulm said in Qt5.11.2, QSqlDatabase, QMYSQL, Driver not loaded:

libmysqlclient.20.dylib

I've found what I think is the correct library on my system:

    /usr/local/Cellar/mariadb/10.2.6/lib/libmariadb.dylib

I then tried:

    sudo ln -s /usr/local/Cellar/mariadb/10.2.6/lib/libmariadb.dylib /usr/local/lib/libmysqlclient.20.dylib

Re-ran in debug and the problem has changed, looks like I'm using the wrong library now:

2018-10-11 09:15:08.331712+0100 SimonQtWidgets[1644:135071] Got keys from plugin meta data ("QPSQL7", "QPSQL")
2018-10-11 09:15:08.331726+0100 SimonQtWidgets[1644:135071] QFactoryLoader::QFactoryLoader() checking directory path "/Users/simonplatten/build-SimonQtWidgets-Desktop_Qt_5_11_2_clang_64bit-Debug/SimonQtWidgets.app/Contents/MacOS/sqldrivers" ...
2018-10-11 09:15:08.347152+0100 SimonQtWidgets[1644:135071] Cannot load library /Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib: (dlopen(/Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib, 133): Library not loaded: /usr/local/mysql/lib/libmysqlclient.20.dylib
  Referenced from: /Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib
  Reason: Incompatible library version: libqsqlmysql.dylib requires version 20.0.0 or later, but libmysqlclient.20.dylib provides version 3.0.0)
2018-10-11 09:15:08.347182+0100 SimonQtWidgets[1644:135071] QLibraryPrivate::loadPlugin failed on "/Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib" : "Cannot load library /Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib: (dlopen(/Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib, 133): Library not loaded: /usr/local/mysql/lib/libmysqlclient.20.dylib\n  Referenced from: /Users/sim
onplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib\n  Reason: Incompatible library version: libqsqlmysql.dylib requires version 20.0.0 or later, but libmysqlclient.20.dylib provides version 3.0.0)"
2018-10-11 09:15:08.347201+0100 SimonQtWidgets[1644:135071] QSqlDatabase: QMYSQL driver not loaded
2018-10-11 09:15:08.347228+0100 SimonQtWidgets[1644:135071] QSqlDatabase: available drivers: QSQLITE QMYSQL QMYSQL3 QPSQL QPSQL7

SGaist

Don't use ln that won't help, use install_name_tool and update the path in libqsqlmysql.dylib to match what you have on your system.

SPlatten

@SGaist, thank you, do you have an example? How do I achieve this?

SGaist

Did you read the tool's help ?

install_name_tool -change /usr/local/mysql/lib/libmysqlclient.20.dylib /path/to/mariadb/libmariadbclient.X.dylib /Users/hasan/Qt5.9.1/5.9.1/clang_64/plugins/sqldrivers/libqsqlmysql.dylib

Note that MariaDB should be a drop-in replacement however I haven't tried to "re-link" to a library that has different name (just a different compatible version number) so you may have other surprises.