MySQL driver detected but not loading on MacOS

SGaist

That's wrong. The same rules apply for the MySQL plugin in Qt 6 than in Qt 5.

Qt has a lot more database plugins that what is provided in the pre-built binaries. Some of them require commercial dependencies that needs to be acquired by the developer/companies that wants to use them so they won't be part of the pre-built binaries either.

Vince2480

@SGaist I could not build Qt from sources, too many errors for me to understand, I'm only a hobby programmer. I read Qt company says 6.2 beta is M1 compliant. therefore I installed with Maintenance tool.

MySql plugins were present in Qt5.9.9 but definitely not in 6.

Now I'm trying to find the libmysql source files, all I can find are binaries Connector/C++ at dev.MySql.com

SGaist

@Vince2480 said in MySQL driver detected but not loading on MacOS:

MySql plugins were present in Qt5.9.9 but definitely not in 6.

And not in 5.14 and 5.15. Oracle has changed its licensing scheme and thus the Qt Company does not provide the pre-built plugin anymore. You can build it yourself for your Qt version if you get the x86_64 version of the connectior.

Vince2480

Ok, I need help building MySql.
Just to be sure what I'm doing is right,
Attempting to build the x86-64 version drivers
I Downloaded the MySql source package with

git clone https://github.com/mysql/mysql-connector-cpp.git
git checkout 8.0

Next I ran cmake

cmake cmakelists.txt

-- The C compiler identification is AppleClang 12.0.5.12050022
-- The CXX compiler identification is AppleClang 12.0.5.12050022
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/cc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/c++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- BIG_ENDIAN: 0
Building version 8.0.26
Building on system: Darwin-20.6.0 (arm64)
Using cmake generator: Unix Makefiles
Using toolset: 
Building 64bit code
Building shared connector library
Configuring CDK as part of MySQL_CONCPP project
-- Looking for SSL library.
CMake Error at cdk/cmake/DepFindSSL.cmake:79 (message):
  Cannot find appropriate system libraries for SSL.  Make sure you've
  specified a supported SSL version.  Consult the documentation for WITH_SSL
  alternatives
Call Stack (most recent call first):
  cdk/cmake/DepFindSSL.cmake:354 (main)
  cdk/cmake/dependency.cmake:42 (include)
  cdk/CMakeLists.txt:96 (find_dependency)

% which openssl                                                   
/opt/homebrew/cellar/openssl@1.1/1.1.1k/bin/openssl

Is it possible OpenSSL isn't M1 compliant?

Vince2480

I think I'm barking up the wrong tree...

SGaist

You need to build that targeting x86_64 not ARM.

Vince2480

@SGaist Are you saying MySql plugin can't be built for M1?

jsulm

@Vince2480 said in MySQL driver detected but not loading on MacOS:

Are you saying MySql plugin can't be built for M1?

No, that's not what @SGaist is saying.
The thing is that you have x86_64 Qt, right? If so, then you also need x86_64 build of the MySql plug-in.

Vince2480

@jsulm I see.

In-Gee

I am also faced with the similar problems and I have got no clear answers from Qt person. In my case, my configuration is

macOS Monterey with Intel cpu,
PostgreSQL is running on docker with the official image Postgres:latest, i.e., PostgreSQL 14.5, which was updated yesterday in my Mac.

The day before yesterday, my code has worked fine. There was no problem. Yesterday, I changed the PostgreSQL docker image to be the newer version, "postgres:latest". No source code of my app has been changed. So, I have tried to remove the Qt installs it again several times.

My final choice is to downgrade the PostgreSQL docker image to the "Postgres:14" for which I wish to work fine. If this treatment works, the QPSQL driver code or driver selection procedure has serious problem conceptually. A complete redesign may be necessary.

Let me give you the result tomorrow.

jsulm

@In-Gee said in MySQL driver detected but not loading on MacOS:

I am also faced with the similar problems

Driver not loaded?
Changing the PostgreSQL server should not have any influence on whether the Qt driver plug-in can be loaded or not. Are you sure you have same problem as in this thread? Did you verify that the PostgreSQL plug-in can't be loaded?

In-Gee

@jsulm I just fixed the problem. Let me just explain how I found the problem step by step. (macOS)

I prefer the Docker base PostgreSQL and install the Homebrew version of PostgreSQL. This is convenient to me because every upgrade apps can be done by a single command, $ brew upgrade.
I activated QT_DEBUG_PLUGINS = 1 in the Qt Creator Environment setting. I have struggled to figure out how to do it, because I am a beginner for the Qt development situation. I have not understand what your are talking about.
I followed the detailed debug message and found out the problem is the Qt is looking for the relevant QPSQL library based on the assumption such that the user has installed the PostgreSQL by using the PostgreSQL App.
Problem is here: The Qt engineers could give a priority to the PostgreSQL.App installation but they has to consider the directory search for the users with Homebrew or the other installation methods as well.
So I installed the PostgreSQL.App by downloading from the PostgreSQL website, stop the existing docker, runt the PostgreSQL.App and stop it followed by run the docker again. Then I compiled my source code again and I got it.
It is recommended to consider the configuration the QPSQL driver, and also the other drivers, other mfethod/directory installations. The Unix command, "which", may give the hint to figure out the user preference. I hope the Qt engineers may consider the various situations with little bit clever way.

Thanks for your interests.

jsulm

@In-Gee said in MySQL driver detected but not loading on MacOS:

I hope the Qt engineers may consider the various situations with little bit clever way

You could file a change request in Qt Bug Tracker: https://bugreports.qt.io/secure/Dashboard.jspa

juneleung

I had a similar problem,
When I packaged the postgresql program, it was fine to run it locally, but when I opened the program on another computer, it prompted
"QSqlDatabase: QPSQL driver not loaded.
QSqlDatabase: available drivers: QSQLITE QODBC QODBC3 QPSQL QPSQL7",
it seems that the driver of postgresql is not loaded.
Why this the problem happened? Is there something wrong with the package? How should I set it?
Could anyone guide me how to solve it?

SGaist

@juneleung hi and welcome to devnet,

You have to deploy the PostgreSQL library along your application. Did you use macdeployqt to deploy your application ?

juneleung

Hi @SGaist
Yes, i have use macdeployqt to make it to a dmg file.
but when open it in another MacBook, it cant link with sql and notice driven not loaded driven not loaded.

artwaw

@juneleung AFAIR you need to manually deploy libpq.5.xx.dylib and relink your binary inside the .app to link to that - macdeployqt will not do it for you. I remember scripting that when I wrote a tool to interface with PostgreSQL. You'd need install-name-tool to do that.

SGaist

@artwaw not the binary, the plugin.

artwaw

@SGaist You are right, of course, it's been a while since I dipped my fingers into this abyss.

At any rate, I dug out my script, it will require some polishing but the gist is:

#!/bin/zsh
cp -fR ~/cpp/build-appName-Desktop_Qt_5_15_2_clang_64bit-Release/appName.app .
macdeployqt appName.app -verbose=1 -always-overwrite
cp -f *.dylib appName.app/Contents/Frameworks/
install_name_tool -change /Applications/Postgres.app/Contents/Versions/9.6/lib/libpq.5.dylib @executable_path/../Frameworks/libpq.5.dylib appName/Contents/PlugIns/sqldrivers/libqsqlpsql.dylib
install_name_tool -change libpq.5.dylib @executable_path/../Frameworks/libpq.5.dylib appName.app/Contents/MacOS/appName

That works under assumption that you have all necessary Postgres files and your .app package in the same folder as the script. Or - at least - was working for the Qt 5.15.2.

I replaced my app name with appName.

juneleung

@artwaw Hi,
I dont have any Postgres files' *.dylib in my app dir and my app/Contents/Plugins/sqldrivers/ folder dont have libqsqlpsql.dylib, only libqsqlite.dylib libqsqlodbc.dylib and libqsqlpsql.dylib.
Where to make it create this dylib or where to copy it ? Which dylibs are postgresql needed?
Thanks!