MySql plugin not working for release version of a project

Marcusdrl

I have MySql plugin installed and it works fine with my debug version of this project, im trying to deploy it right now and i cant make the release version work since it doesnt show 'MYSQL' as a viable option of a database. Ive built it following the documentation https://doc.qt.io/qt-6/sql-driver.html , and i didnt noticed anything mentioning that i had to make another build for the release version and im not sure what to do now... any help would be appreciated.

Christian Ehrlicher

So do you have actually build a release qt-sql plugin - is there a mysql plugin without a 'd' suffix?

mchinand

Re-run cmake and add -DCMAKE_BUILD_TYPE=Release to the command line.
You can also set the environment variable QT_DEBUG_PLUGINS=1 and check the output when it tries to load your plugin. With release build of your app and debug-built plugin, you will probably get something like the following, note the part at the end (this is for the debug-build of the QtCompany-supplied Postgres plugin):

QFactoryLoader::QFactoryLoader() looking at "C:/Qt/5.14.2/msvc2017_64/plugins/sqldrivers/qsqlpsqld.dll"
Found metadata in lib C:/Qt/5.14.2/msvc2017_64/plugins/sqldrivers/qsqlpsqld.dll, metadata=
{
    "IID": "org.qt-project.Qt.QSqlDriverFactoryInterface",
    "MetaData": {
        "Keys": [
            "QPSQL7",
            "QPSQL"
        ]
    },
    "archreq": 1,
    "className": "QPSQLDriverPlugin",
    "debug": true,
    "version": 331264
}


"The plugin 'C:/Qt/5.14.2/msvc2017_64/plugins/sqldrivers/qsqlpsqld.dll' uses incompatible Qt library. (Cannot mix debug and release libraries.)" 
         not a plugin

Marcusdrl

@Christian-Ehrlicher hi, theres isnt actually, this is the one i got:

As you can see i only have the debug version, i just dont know how to build the release one...

Marcusdrl

@mchinand said in MySql plugin not working for release version of a project:

Re-run cmake and add -DCMAKE_BUILD_TYPE=Release to the command line.

Hi @mchinand, i've tried it but it didnt changed anything, it worked but it didnt created any new file... maybe i have to delete my build-sqldrivers folder?

eyllanesc

This post is deleted!

SGaist

Hi,

Might be a silly question but did you actually also do the build and install calls afterward ?

Marcusdrl

@SGaist said in MySql plugin not working for release version of a project:

Hi,

Might be a silly question but did you actually also do the build and install calls afterward ?

Hi, and yes... but now that i noticed it didnt went well as i thought it actually failed locating a file:

It didnt created the qsqlmysql.dll

SGaist

From the looks of it you built directly in the sources.

What I would recommend is doing like the documentation suggests: create a build folder and redo your build for release in there so there's no leftover from your previous build that might interfere.

Marcusdrl

So i figured out why it wasnt installing, i forgot to initialize a vcvarsall.bat instance inside my MSVCx64 CMD, everything working now, thank you for your attention @SGaist

SGaist

Tricky one !

Glad you found out and thanks for sharing :-)