Qt5.11.2, QSqlDatabase, QMYSQL, Driver not loaded

SPlatten

I have the following code to connect to a MariaDB database on my local development system. The development system is an iMAC:

Model Name:  iMac
Model Identifier:  iMac17,1
Processor Name:  Intel Core i7
Processor Speed:  4 GHz
Number of Processors: 1
Total Number of Cores: 4
L2 Cache (per Core):  256 KB
L3 Cache:  8 MB
Memory: 16 GB
Boot ROM Version: IM171.0157.B00
SMC Version (system):	2.34f2

I am trying to connect to the database with:

QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL");
db.setHostName("Simons-iMac.local");
db.setDatabaseName("timekpr");
db.setUserName("timekpr");
db.setPassword("timekpr");

if ( !db.open() ) {
    qDebug() << db.lastError();
    qFatal( "Failed to connect." );
}
qDebug( "Connected!" );

Unfortunately, the result is:

2018-10-04 18:36:22.414186+0100 SimonQtWidgets[23857:951442] [default] Unable to load Info.plist exceptions (eGPUOverrides)
2018-10-04 18:36:28.995915+0100 SimonQtWidgets[23857:951353] QSqlDatabase: QMYSQL driver not loaded
2018-10-04 18:36:28.995977+0100 SimonQtWidgets[23857:951353] QSqlDatabase: available drivers: QSQLITE QMYSQL QMYSQL3 QPSQL QPSQL7
2018-10-04 18:36:34.533463+0100 SimonQtWidgets[23857:951353] QSqlError("", "Driver not loaded", "Driver not loaded")
2018-10-04 18:36:35.207312+0100 SimonQtWidgets[23857:951353] Failed to connect.

How do I resolve this issue? I can connect to the database using NodeJs on the same system with exactly the same credentials.

SPlatten

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

libmysqlclient.20.dylib

@SGaist , I managed to progress the issue, this is what I did:

Manually create the required folder structure, from /usr/local:

sudo mkdir mysql
cd mysql
sudo mkdir lib
cd lib

Then create a symbolic link to the required library:

sudo ln -s /usr/local/lib/libmysqlclient.dylib /usr/local/mysql/lib/libmysqlclient.20.dylib

Now debugging the same project, the call to open still fails with:

2018-10-12 08:44:19.696706+0100 SimonQtWidgets[1253:117317] loaded library "/Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib"
2018-10-12 08:44:39.663805+0100 SimonQtWidgets[1253:117317] QSqlError("1130", "QMYSQL: Unable to connect", "Host '192.168.1.158' is not allowed to connect to this MariaDB server")
2018-10-12 08:44:40.409469+0100 SimonQtWidgets[1253:117317] Failed to connect.

Now resolved, the issue here was that the call to setHostName was using the host name of the system, I changed this to localhost and now everything works.

SGaist

Hi,

This question has already been asked many times on this forum. Please search it a bit (although you might stumble on more posts about PostgreSQL on macOS)

In any case, run otool -L on the MySQL Qt plugin. You'll likely get at least one path pointing to a location where it can't find the MySQL client library. Use install_name_tool to fix that path and point it to your MariaDB client library.

In any case, you can use the QT_DEBUG_PLUGINS environment variable set to 1 to get more information about what happens when your application tries to load a plugin.

SPlatten

I took your advice and there are many many people asking the same thing, I couldn't find a simple solution for me on the macOS. Why is this such a problem? The instance of MariaDB on my system works fine and I can open it using "wine" and HeidiSQL without any problems, but I cannot connect to it with QSQLDababase.

I have Q5.11.2 installed in ~/Qt/5.11.2/

This is what I tried:

cd  Qt/5.11.2/clang_64/plugins/sqldrivers/

In this folder I have the following:

libqsqlite.dylib
libqsqlite.dylib.dSYM
libqsqlite_debug.dylib
libqsqlmysql.dylib
libqsqlmysql.dylib.dSYM
libqsqlmysql_debug.dylib
libqsqlmysql_debug.dylib.dSYM
libqsqlpsql.dylib
libqsqlpsql.dylib.dSYM
libqsqlpsql_debug.dylib
libqsqlpsql_debug.dylib.dSYM

I tried:

otool -L libqsqlmysql.dylib

Which results in:

libqsqlmysql.dylib:
	libqsqlmysql.dylib (compatibility version 0.0.0, current version 0.0.0)
	@rpath/QtSql.framework/Versions/5/QtSql (compatibility version 5.11.0, current version 5.11.2)
	@rpath/QtCore.framework/Versions/5/QtCore (compatibility version 5.11.0, current version 5.11.2)
	/System/Library/Frameworks/DiskArbitration.framework/Versions/A/DiskArbitration (compatibility version 1.0.0, current version 1.0.0)
	/System/Library/Frameworks/IOKit.framework/Versions/A/IOKit (compatibility version 1.0.0, current version 275.0.0)
	/usr/local/mysql/lib/libmysqlclient.20.dylib (compatibility version 20.0.0, current version 20.0.0)
	/usr/lib/libc++.1.dylib (compatibility version 1.0.0, current version 307.5.0)
	/usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1238.50.2)

then:

otool -L libqsqlmysql_debug.dylib

Which results in:

libqsqlmysql_debug.dylib:
	libqsqlmysql_debug.dylib (compatibility version 0.0.0, current version 0.0.0)
@rpath/QtSql.framework/Versions/5/QtSql (compatibility version 5.11.0, current version 5.11.2)
@rpath/QtCore.framework/Versions/5/QtCore (compatibility version 5.11.0, current version 5.11.2)
	/System/Library/Frameworks/DiskArbitration.framework/Versions/A/DiskArbitration (compatibility version 1.0.0, current version 1.0.0)
	/System/Library/Frameworks/IOKit.framework/Versions/A/IOKit (compatibility version 1.0.0, current version 275.0.0)
	/usr/local/mysql/lib/libmysqlclient.20.dylib (compatibility version 20.0.0, current version 20.0.0)
	/usr/lib/libc++.1.dylib (compatibility version 1.0.0, current version 307.5.0)
	/usr/lib/libSystem.B.dylib (compatibility version 1.0.0, current version 1238.50.2)

I then rebuilt the project, results almost the same:

18:20:30: Debugging starts
2018-10-08 18:20:34.165604+0100 SimonQtWidgets[750:27393] [default] Unable to load Info.plist exceptions (eGPUOverrides)
2018-10-08 18:20:37.754057+0100 SimonQtWidgets[750:27293] QSqlDatabase: QMYSQL driver not loaded
2018-10-08 18:20:37.754278+0100 SimonQtWidgets[750:27293] QSqlDatabase: available drivers: QSQLITE QMYSQL QMYSQL3 QPSQL QPSQL7
2018-10-08 18:20:42.086803+0100 SimonQtWidgets[750:27293] QSqlError("", "Driver not loaded", "Driver not loaded")
2018-10-08 18:20:43.026402+0100 SimonQtWidgets[750:27293] Failed to connect.

Can anyone help?

SGaist

What do you get if you start your application with the QT_DEBUG_PLUGINS environment variable set to 1 ?

SPlatten

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

QT_DEBUG_PLUGINS

I did this:

Opened a terminal
Typed: export QT_DEBUG_PLUGINS=1

Started application in Qt with debug and single stepped the following lines:

QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL");
db.setHostName("Simons-iMac.local");
db.setDatabaseName("timekpr");
db.setUserName("timekpr");
db.setPassword("timekpr");

When I stepped over the first line I got:

    2018-10-09 08:28:39.328815+0100 SimonQtWidgets[934:47867] QSqlDatabase: QMYSQL driver not loaded

SGaist

What would be interesting is to have the log that was generated about the plugin loading phase.

SPlatten

What do I need to do in order to get you that log?

SGaist

Since you are using Qt Creator, look at the output panel.

SPlatten

Specifically which panel are you referring to?

I don't see anything in the "Debugger Console", if I enable the "Debugger Log" I see:

dNOTE: INFERIOR RUN REQUESTED
sRun requested...
dState changed from InferiorStopOk(11) to InferiorRunRequested(7) [master]
<73executeNext({"token":73})

(lldb) script theDumper.executeNext({"token":73})
@
result={token="73",}@
@
event={type="1",data="0x7fea5d161f90 Event: broadcaster = 0x7fea5a85fa38 (lldb.process), type = 0x00000001 (state-changed), data = { process = 0x7fea5a85fa00 (pid = 2567), state = running}",msg="None",flavor="Process::ProcessEventData",state="running",bp="No value"}@
@
state="running"@
@
event={type="4",data="0x7fea5b425a58 Event: broadcaster = 0x7fea5a85fa38 (lldb.process), type = 0x00000004 (stdout-available), data = { process = 0x7fea5a85fa00 (pid = 2567), state = running}",msg="None",flavor="Process::ProcessEventData",state="running",bp="No value"}@
@
output={channel="stdout",data="323031382d31302d30392031303a30343a30352e3739383731312b303130302053696d6f6e5174576964676574735b323536373a3338393637385d205153716c44617461626173653a20514d5953514c20647269766572206e6f74206c6f616465640d0a323031382d31302d30392031303a30343a30352e3739383736372b303130302053696d6f6e5174576964676574735b323536373a3338393637385d205153716c44617461626173653a20617661696c61626c6520647269766572733a205153514c49544520514d5953514c20514d5953514c3320515053514c20515053514c370d0a"}@
@
event={type="4",data="0x7fea5d04e788 Event: broadcaster = 0x7fea5a85fa38 (lldb.process), type = 0x00000004 (stdout-available), data = { process = 0x7fea5a85fa00 (pid = 2567), state = running}",msg="None",flavor="Process::ProcessEventData",state="running",bp="No value"}@
@
output={channel="stdout",data=""}@
73^
dNOTE: INFERIOR RUN OK
sRunning.
dState changed from InferiorRunRequested(7) to InferiorRunOk(8) [master]
2018-10-09 10:04:05.798711+0100 SimonQtWidgets[2567:389678] QSqlDatabase: QMYSQL driver not loaded
2018-10-09 10:04:05.798767+0100 SimonQtWidgets[2567:389678] QSqlDatabase: available drivers: QSQLITE QMYSQL QMYSQL3 QPSQL QPSQL7
@
event={type="1",data="0x7fea5d071a40 Event: broadcaster = 0x7fea5a85fa38 (lldb.process), type = 0x00000001 (state-changed), data = { process = 0x7fea5a85fa00 (pid = 2567), state = stopped}",msg="None",flavor="Process::ProcessEventData",state="stopped",bp="No value"}@
@
state="stopped"@
dNOTE: INFERIOR SPONTANEOUS STOP
sStopped.
dState changed from InferiorRunOk(8) to InferiorStopOk(11) [master]
<74fetchThreads({"token":74})

(lldb) script theDumper.fetchThreads({"token":74})
@
result={token="74",threads=[{id="389678",index="0",details="com.apple.main-thread",stop-reason="plancomplete",state="unknown",name="None",frame={pc="0x1000038d6",addr="0x1000038d6",fp="0x7ffeefbffa00",func="main",line="13",fullname="/Users/simonplatten/build-SimonQtWidgets-Desktop_Qt_5_11_2_clang_64bit-Debug/../SimonQtWidgets/main.cpp",file="/Users/simonplatten/build-SimonQtWidgets-Desktop_Qt_5_11_2_clang_64bit-Debug/../SimonQtWidgets/main.cpp"}},{id="389776",index="1",details="None",stop-reason="none",state="unknown",name="None",frame={pc="0x7fff753495be",addr="0x7fff753495be",fp="0x70000e3fefd0",func="__workq_kernreturn",line="0",fullname="",file=""}},{id="389777",index="2",details="None",stop-reason="none",state="unknown",name="None",frame={pc="0x7fff753495be",addr="0x7fff753495be",fp="0x70000e481fd0",func="__workq_kernreturn",line="0",fullname="",file=""}},{id="389783",index="3",details="None",stop-reason="none",state="unknown",name="None",frame={pc="0x7fff753495be",addr="0x7fff753495be",fp="0x70000e504fd0",func="__workq_kernreturn",line="0",fullname="",file=""}},],current-thread-id="389678"}@
74^
<75fetchStack({"context":"","nativemixed":0,"stacklimit":20,"token":75})

(lldb) script theDumper.fetchStack({"context":"","nativemixed":0,"stacklimit":20,"token":75})
@
result={token="75",stack={current-thread="389678",frames=[{pc="0x1000038d6",level="0",address="0x1000038d6",function="main",line="13",file="/Users/simonplatten/build-SimonQtWidgets-Desktop_Qt_5_11_2_clang_64bit-Debug/../SimonQtWidgets/main.cpp"},{pc="0x7fff7520f085",level="1",address="0x7fff7520f085",function="start",line="0",file=""},{pc="0x7fff7520f085",level="2",address="0x7fff7520f085",function="start",line="0",file=""},],hasmore="0",limit="20"}}@
75^
<76activateFrame({"index":0,"thread":389678,"token":76})
<77fetchVariables({"autoderef":1,"context":"","displaystringlimit":"100","dyntype":1,"expanded":["inspect","local","watch","return"],"fancy":1,"formats":{},"nativemixed":0,"partialvar":"","passexceptions":0,"qobjectnames":1,"stringcutoff":"10000","token":77,"typeformats":{},"watchers":[]})
(lldb) script theDumper.activateFrame({"index":0,"thread":389678,"token":76})
@
token("76")@
@
result={token="76",}@
(lldb) script theDumper.fetchVariables({"autoderef":1,"context":"","displaystringlimit":"100","dyntype":1,"expanded":["inspect","local","watch","return"],"fancy":1,"formats":{},"nativemixed":0,"partialvar":"","passexceptions":0,"qobjectnames":1,"stringcutoff":"10000","token":77,"typeformats":{},"watchers":[]})
@
result={token="77",data=[{name="[statics]",iname="local.[statics]",numchild="1",value="",},{iname="local.db",name="db",address="0x7ffeefbff988",numchild="1",type="QSqlDatabase",value="",},{iname="local.w",name="w",address="0x7ffeefbff9a0",numchild="1",type="clsMainWnd",valueencoded="utf16",value="63006c0073004d00610069006e0057006e006400",},{iname="local.a",name="a",address="0x7ffeefbff9e0",numchild="1",type="QApplication",value="",},{iname="local.argv",name="argv",numchild="1",type="char **",valueencoded="itemcount",value="1",},{iname="local.argc",name="argc",address="0x7ffeefbff9f8",numchild="0",type="int",value="1",},],partial="0"}@
76^
77^
<Rebuild Watchmodel 12 @ 10:04:06.112 [11580ms] >
sFinished retrieving data

SPlatten

@SGaist , is this the output you were referring to?

SGaist

No, I never mentioned the debugger output. It's the application output panel that you must take a look at.

SPlatten

@SGaist, the contents of the application output panel was posted with my first post:

   2018-10-09 13:18:16.095404+0100 SimonQtWidgets[2734:287529] [default] Unable to load Info.plist exceptions (eGPUOverrides)
   2018-10-09 13:18:20.493598+0100 SimonQtWidgets[2734:287440] QSqlDatabase: QMYSQL driver not loaded
   2018-10-09 13:18:20.493843+0100 SimonQtWidgets[2734:287440] QSqlDatabase: available drivers: QSQLITE QMYSQL QMYSQL3 QPSQL QPSQL7
   2018-10-09 13:19:25.430180+0100 SimonQtWidgets[2734:287440] QSqlError("", "Driver not loaded", "Driver not loaded")
   2018-10-09 13:19:25.986168+0100 SimonQtWidgets[2734:287440] Failed to connect.

SGaist

Where did you define QT_DEBUG_PLUGINS ?

SPlatten

@SGaist, I did the following in a terminal window:

    open ~/.bash_profile

In the editor, the bash_profile file was empty I added:

    export QT_DEBUG_PLUGINS=1

Saved the file and closed the editor. I then ran:

    source ~/.bash_profile

I closed the terminal, then re-opened to check that the variable was present by typing:

    export

This is what was displayed:

    declare -x Apple_PubSub_Socket_Render="/private/tmp/com.apple.launchd.hLeo6KAahB/Render"
    declare -x DISPLAY="/private/tmp/com.apple.launchd.FHCnpoFY18/org.macosforge.xquartz:0"
    declare -x HOME="/Users/simonplatten"
    declare -x LANG="en_GB.UTF-8"
    declare -x LOGNAME="simonplatten"
    declare -x OLDPWD
    declare -x         PATH="/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/share/dotnet:/opt/X11/bin:/Library/Frameworks/Mono.framework/Versions/Current/Commands"
    declare -x PWD="/Users/simonplatten"
    declare -x QT_DEBUG_PLUGINS="1"
    declare -x SHELL="/bin/bash"
    declare -x SHLVL="1"
    declare -x SSH_AUTH_SOCK="/private/tmp/com.apple.launchd.DmRhtwquji/Listeners"
    declare -x TERM="xterm-256color"
    declare -x TERM_PROGRAM="Apple_Terminal"
    declare -x TERM_PROGRAM_VERSION="421"
    declare -x TERM_SESSION_ID="FDD4C847-385E-449E-A882-C0AC074D406E"
    declare -x TMPDIR="/var/folders/sr/s5hzkrzs7n92phmkzbrs0g_r0000gn/T/"
    declare -x USER="simonplatten"
    declare -x XPC_FLAGS="0x0"
    declare -x XPC_SERVICE_NAME="0"

SGaist

You should rather do that in the Run part of the Project panel.

Because unless you either logged out or restart Qt Creator from the same terminal you ran your export from, it won't see the new variable.

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.