(MySQL) qsqlmysql.dll doesn't get created.

[SGaist]

Hi and welcome to devnet,

The build folder should be out of source and out of installation tree.

There's no need for CMAKE_INSTALL_PREFIX, qt-cmake is configured to have that knowledge already.

[Thelonious]

@SGaist

Hi, and thank you for your response.

I can remove CMAKE_INSTALL_PREFIX from my command, delete CMakeCache.txt and rerun?

The build folder is the first one listed in the command and that should point to a folder outside fo C:\QT\ , correct?

[SGaist]

It can be in a dedicated folder in the Qt folder, just not directly in one of the 6.X or 5.X.

You can create a build_driver folder and do everything there.

Out of curiosity, why not use Qt's provided cmake ?

[Thelonious]

@SGaist

I can use the set PATH command before I run cmake --build . ?

I wasn't aware that I could. Some of the other researching I've done showed that there used to be a .pro file for the sqldrivers and you could include the paths for ..\include and ..\lib in there and run qmake on the file but those seem outdated.

The new command i'm running:

after building the libraries I simply

> set PATH="C:\buildFolder"
> cmake --build .

the build still returns

MSBuild version 17.5.1+f6fdcf537 for .NET Framework

  Automatic MOC for target QMYSQLDriverPlugin
cl : command line  error D8016: '/O2' and '/RTC1' command-line options are incompatible [C:\Qt\6.4.3\msvc2019_64\bin\my
sql\QMYSQLDriverPlugin.vcxproj]
  Automatic MOC for target QODBCDriverPlugin
cl : command line  error D8016: '/O2' and '/RTC1' command-line options are incompatible [C:\Qt\6.4.3\msvc2019_64\bin\od
bc\QODBCDriverPlugin.vcxproj]
  Automatic MOC for target QSQLiteDriverPlugin
cl : command line  error D8016: '/O2' and '/RTC1' command-line options are incompatible [C:\Qt\6.4.3\msvc2019_64\bin\sq
lite\QSQLiteDriverPlugin.vcxproj]

And once again thank you for your help!

[SGaist]

It seems you have now things interfering. Did you do a clean configure/build of the drivers ?

[Thelonious]

@SGaist

Yes I believe so. Before I made this post I uninstalled QT 6.4.3 and reinstalled it to get a clean folder.

I must admit I may have misinterpreted your previous suggestion. When you say use a build folder outside of QT; that's where you want me to build those plugin files to, correct?

copy qt-make.txt to the build folder, then :

C:\buildfolder>  qt-cmake C:\QT\6.4.3\Src\qtbase\src\plugins\sqldrivers -DMySQL_INCLUDE_DIR="C:\Program Files\MySQL\MySQL Connector c 6.1\include" -DMySQL_LIBRARY="C:\Program Files\MySQL\MySQL Connector c 6.1\lib\libmysql.lib

[SGaist]

You don't need to copy any files. Just use the full path to the executable.

[Thelonious]

@SGaist

Oh, so cmake --build C:\buildfolder ?

Error: could not load cache

[SGaist]

mkdir build_folder
cd build_folder
C:/Qt/6.4.3/msvc2019_64/bin/qt-cmake <insert options here> c:/Qt/6.4.3/Src/qtbase/src/plugins/sqldrivers/mysql/
c:/Qt/6.4.3/msvc2019_64/bin/qt-cmake --build .

[Thelonious]

@SGaist

Understood.

Went ahead and did that and it built the plugins in build_folder which is inside C:\Qt\6.4.3\msvc2019_65\ but not in the main path

Then I tried to run

C:\Qt\6.4.3\msvc2019_64\build_folder> cmake --build .

*qt-cmake --build . threw an error

the output remains

While I was waiting for your response (thanks again!) I searched for an answer to those errors and it was suggested that I might need to modify the CMakeLists.txt at ...\src\plugins\sqldrivers . But beyond that i'm stuck,

[Thelonious]

@SGaist

I think I was able to get a good build using

C:\Qt\6.4.3\msvc2019_64\build-sqldrivers>qt-cmake -S C:\Qt\6.4.3\Src\qtbase\src\plugins\sqldrivers -B .

OUTPUT:

-- Selecting Windows SDK version 10.0.22621.0 to target Windows 10.0.19044.



-- Configuring done (1.9s)
-- Generating done (0.4s)
CMake Warning:
  Manually-specified variables were not used by the project:

    CMAKE_TOOLCHAIN_FILE


-- Build files have been written to: C:/Qt/6.4.3/msvc2019_64/build-sqldrivers

and cmake --install . yielded

CMake Error: Could not find CMAKE_ROOT !!!
CMake has most likely not been installed correctly.
Modules directory not found in
C:/Qt/6.4.3/msvc2019_64/share/cmake-3.26
-- Install configuration: "RelWithDebInfo"
-- Up-to-date: C:/Qt/6.4.3/msvc2019_64/lib/cmake/Qt6Sql/Qt6QMYSQLDriverPluginConfig.cmake
-- Up-to-date: C:/Qt/6.4.3/msvc2019_64/lib/cmake/Qt6Sql/Qt6QMYSQLDriverPluginConfigVersion.cmake
-- Up-to-date: C:/Qt/6.4.3/msvc2019_64/lib/cmake/Qt6Sql/Qt6QMYSQLDriverPluginConfigVersionImpl.cmake
-- Installing: C:/Qt/6.4.3/msvc2019_64/./plugins/sqldrivers/qsqlmysql.dll
-- Installing: C:/Qt/6.4.3/msvc2019_64/lib/cmake/Qt6Sql/Qt6QMYSQLDriverPluginTargets.cmake
-- Installing: C:/Qt/6.4.3/msvc2019_64/lib/cmake/Qt6Sql/Qt6QMYSQLDriverPluginTargets-relwithdebinfo.cmake
-- Installing: C:/Qt/6.4.3/msvc2019_64/lib/cmake/Qt6Sql/Qt6QMYSQLDriverPluginAdditionalTargetInfo.cmake
-- Installing: C:/Qt/6.4.3/msvc2019_64/lib/cmake/Qt6Sql/Qt6QODBCDriverPluginConfig.cmake
-- Installing: C:/Qt/6.4.3/msvc2019_64/lib/cmake/Qt6Sql/Qt6QODBCDriverPluginConfigVersion.cmake
-- Installing: C:/Qt/6.4.3/msvc2019_64/lib/cmake/Qt6Sql/Qt6QODBCDriverPluginConfigVersionImpl.cmake
CMake Error at odbc/cmake_install.cmake:45 (file):
  file INSTALL cannot find
  "C:/Qt/6.4.3/msvc2019_64/build-sqldrivers/plugins/sqldrivers/qsqlodbc.dll":
  No such file or directory.
Call Stack (most recent call first):
  cmake_install.cmake:42 (include)

Which built qsqlmysql.dll and put it in C:\Qt\6.4.3\msvc2019_64\plugins\sqldrivers

However;

My project still doesn't load QMYSQL

Application Output:

QList("QSQLITE", "QODBC", "QPSQL")

[jsulm]

@Thelonious said in (MySQL) qsqlmysql.dll doesn't get created.:

My project still doesn't load QMYSQL

Then set QT_DEBUG_PLUGINS to 1 before running your app and check the output to see why the MySQL plug-in was not loaded. Probably the mysql client library could not be found.

[Christian Ehrlicher]

@jsulm said in (MySQL) qsqlmysql.dll doesn't get created.:

Probably the mysql client library could not be found

In this case the plugin would at least show up in the available plugins list.
I would guess it's the wrong Qt directory.

[Thelonious]

@Christian-Ehrlicher

So I should move my recently created qsqlmysql.dll into the same folder as my project executable? Do I need to move my plugins from C:\Qt\6.4.3\msvc2019_64\build-sqldrivers?

Thanks for your help,

[Christian Ehrlicher]

@Thelonious said in (MySQL) qsqlmysql.dll doesn't get created.:

So I should move my recently created qsqlmysql.dll into the same folder as my project executable?

I never said this. I just think that C:\Qt\6.4.3\ is not the Qt you're using while running your executable. When you would have followed @jsulm's advise we would have known more.

[Thelonious]

@Christian-Ehrlicher

qt.core.plugin.factoryloader: looking at "C:/Qt/6.4.3/msvc2019_64/plugins/sqldrivers/qsqlmysql.dll"
qt.core.plugin.loader: Found metadata in lib C:/Qt/6.4.3/msvc2019_64/plugins/sqldrivers/qsqlmysql.dll, metadata=
{
    "IID": "org.qt-project.Qt.QSqlDriverFactoryInterface",
    "MetaData": {
        "Keys": [
            "QMYSQL",
            "QMARIADB"
        ]
    },
    "archlevel": 0,
    "className": "QMYSQLDriverPlugin",
    "debug": false,
    "version": 394240
}


qt.core.plugin.factoryloader: "The plugin 'C:/Qt/6.4.3/msvc2019_64/plugins/sqldrivers/qsqlmysql.dll' uses incompatible Qt library. (Cannot mix debug and release libraries.)" 
         not a plugin

[Christian Ehrlicher]

@Thelonious said in (MySQL) qsqlmysql.dll doesn't get created.:

qt.core.plugin.factoryloader: "The plugin 'C:/Qt/6.4.3/msvc2019_64/plugins/sqldrivers/qsqlmysql.dll' uses incompatible Qt library. (Cannot mix debug and release libraries.)"
not a plugin

So you only compiled the release plugin but running a debug app.

[Thelonious]

@Christian-Ehrlicher
I apologize; the QT help article on building MySQL drivers doesn't specify how to make a debug version. Can you please point me somewhere that explains the difference or shows me hot to make the debug plugin?

[Christian Ehrlicher]

Either open the generated solution and build the debug version (can also be done from the command line but I don't remember the commands) or use -G Ninja or -G NMake Makefiles for the cmake generator - they both produce rules to create both plugins directly. Maybe we should add this to the documentation. MSBuild is not meant to be run on the command line and therefore has a lot of strange switches...

[Thelonious]

@Christian-Ehrlicher
Interestingly enough after I run qt-cmake the only solution file I get is QSQLiteDriverPlugin.sln. Seems like a lot of people are having problems building the new driver.

How would I got about installing ninja for use with cmake? I downloaded CMake separately.

-Thanks