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

Thelonious

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

Christian Ehrlicher

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

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

If you want to use ninja, download it and put it in your PATH

Thelonious

@Christian-Ehrlicher
Done and done.

Running the qt-cmake -G Ninja <arguments> is returning

-- The CXX compiler identification is unknown
-- The C compiler identification is unknown
-- The ASM compiler identification is unknown
-- Didn't find assembler
CMake Error at CMakeLists.txt:7 (project):
  No CMAKE_CXX_COMPILER could be found.

  Tell CMake where to find the compiler by setting either the environment
  variable "CXX" or the CMake cache entry CMAKE_CXX_COMPILER to the full path
  to the compiler, or to the compiler name if it is in the PATH.

Taking a look at my CMakeList.txt at ...\sqldrivers and can't find the CMAKE_CXX_COMPILER entry. I assume I need to set it to
C:\Program Files\Microsoft Visual Studio\2022\Community\VC\Tools\MSVC\14.35.32215\bin\Hostx64\x64\cl.exe

Christian Ehrlicher

@Thelonious You don't need it to set to anything. You have to make sure that the msvc environment is properly set up the same way you did it in your previous attempts.

Thelonious

@Christian-Ehrlicher

Still getting the same error.

I might have to use SQLite while I build my code and come back to this. Something about my environment is just not right and the QT help article on building MySQL drivers seems to be missing a lot of explanations and is giving examples for a specific and out-of-date MySQL environment. The help article doesn't specify what directory any of these commands should be run from.

Christian Ehrlicher

Since you managed to set up your compiler environment before and no no longer I don't know what you're doing wrong. Call the correct vsvars batch file to set up your msvc compiler...