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

Thelonious

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...

Thelonious

@Christian-Ehrlicher

The difference is I'm having to add

-G Ninja

to qt-cmake.

I can make the plugins without it but when it comes time to --build the driver I get

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]

SGaist

Your system is unclean, there's no reason for the projects to be in the bin folder of your Qt installation.

Thelonious

@SGaist qt-cmake resides in the bin folder. Everything i'm creating/building is in an adjacent "build-sqldrivers" folder at

C:\Qt\6.4.3\msvc2019_64\

SGaist

You really should stay out of the source and the installation folders.

Thelonious

@SGaist The help article at https://doc.qt.io/qt-6/sql-driver.html literally shows the driver building directory as bin.

Pulled directly from the article

C:\Qt\6.0.0\mingw81_64\bin\qt-cmake -G Ninja C:\Qt\6.0.0\Src\qtbase\src\plugins\sqldrivers -DMySQL_INCLUDE_DIR="C:\mysql-8.0.22-winx64\include" -DMySQL_LIBRARY="C:\mysql-8.0.22-winx64\lib\libmysql.lib" -DCMAKE_INSTALL_PREFIX="C:\Qt\6.0.0\mingw81_64"
Configure summary:

Qt Sql Drivers:
  DB2 (IBM) .............................. no
  InterBase .............................. no
  MySql .................................. yes
  OCI (Oracle) ........................... no
  ODBC ................................... yes
  PostgreSQL ............................. no
  SQLite ................................. yes
    Using system provided SQLite ......... no

-- Configuring done
-- Generating done
-- Build files have been written to: C:/build-qt6-sqldrivers

It feels as though MySQL has taken a tangent from QT support; it's clear they aren't working closely together. I can go ahead and write my program using SQLite and revisit this in the future because i'm all out of ideas.

I really do appreciate all of yalls help though, there were a few moments when I thought I almost had it.

SGaist

The last line is important: everything happens in ˋc:/build-qt6-sqldrivers`.

Thelonious

@SGaist
I'm going reinstall Qt and try again.

I'll open up a cmd prompt
C:\mysql
and then invoke qt-cmake using it's path

C:\Qt\6.4.3\msvc2019_64\bin\qt-cmake

I'll let you know how it goes. Ninja won't install on my system, give some sort of error regarding Microsoft Store.

SGaist

Are you installing it through the Qt installer ?

Thelonious

@SGaist It is bundled with Qt in the C:\Qt\Tools\Ninja\ folder but I can't "install" it. I tried searching for an answer it seems that its blocked by Microsoft Defender or something else in my environment that I can't disable. Do you think the drivers can be built without it?

BTW, i'm a linux guy at heart and I'm probably going to try to set my Ubuntu environment at home for this.

SGaist

Then there's nothing more you need to do. It should just work (tm). Ninja should be available.

On Linux you can use your distribution's Qt dev packages. It will be easier.