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Qt5.11.2, QSqlDatabase, QMYSQL, Driver not loaded

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  • SGaistS Offline
    SGaistS Offline
    SGaist
    Lifetime Qt Champion
    wrote on last edited by
    #27

    It's not supposed to change anything in the application execution. The goal is to provide you with additional information about what is happening when plugins are getting or not loaded and from there help find what might be going wrong.

    Interested in AI ? www.idiap.ch
    Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

    1 Reply Last reply
    1
    • SPlattenS Offline
      SPlattenS Offline
      SPlatten
      wrote on last edited by
      #28

      @SGaist said in Qt5.11.2, QSqlDatabase, QMYSQL, Driver not loaded:

      QT_DEBUG_PLUGINS

      With QT_DEBUG_PLUGINS added to the environment the output when single stepping over:

          QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL");
      

      Is:

      2018-10-11 08:28:13.253913+0100 SimonQtWidgets[1031:41669] Got keys from plugin meta data ("QPSQL7", "QPSQL")
      2018-10-11 08:28:13.253927+0100 SimonQtWidgets[1031:41669] QFactoryLoader::QFactoryLoader() checking directory path "/Users/simonplatten/build-SimonQtWidgets-Desktop_Qt_5_11_2_clang_64bit-Debug/SimonQtWidgets.app/Contents/MacOS/sqldrivers" ...
      2018-10-11 08:28:13.255823+0100 SimonQtWidgets[1031:41669] Cannot load library /Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib: (dlopen(/Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib, 133): Library not loaded: /usr/local/mysql/lib/libmysqlclient.20.dylib
        Referenced from: /Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib
        Reason: image not found)
      2018-10-11 08:28:13.255844+0100 SimonQtWidgets[1031:41669] QLibraryPrivate::loadPlugin failed on "/Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib" : "Cannot load library /Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib: (dlopen(/Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib, 133): Library not loaded: /usr/local/mysql/lib/libmysqlclient.20.dylib\n  Referenced from: /Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib\n  Reason: image not found)"
      2018-10-11 08:28:13.255
      859+0100 SimonQtWidgets[1031:41669] QSqlDatabase: QMYSQL driver not loaded
      2018-10-11 08:28:13.255885+0100 SimonQtWidgets[1031:41669] QSqlDatabase: available drivers: QSQLITE QMYSQL QMYSQL3 QPSQL QPSQL7
      

      Kind Regards,
      Sy

      jsulmJ 1 Reply Last reply
      0
      • SPlattenS SPlatten

        @SGaist said in Qt5.11.2, QSqlDatabase, QMYSQL, Driver not loaded:

        QT_DEBUG_PLUGINS

        With QT_DEBUG_PLUGINS added to the environment the output when single stepping over:

            QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL");
        

        Is:

        2018-10-11 08:28:13.253913+0100 SimonQtWidgets[1031:41669] Got keys from plugin meta data ("QPSQL7", "QPSQL")
        2018-10-11 08:28:13.253927+0100 SimonQtWidgets[1031:41669] QFactoryLoader::QFactoryLoader() checking directory path "/Users/simonplatten/build-SimonQtWidgets-Desktop_Qt_5_11_2_clang_64bit-Debug/SimonQtWidgets.app/Contents/MacOS/sqldrivers" ...
        2018-10-11 08:28:13.255823+0100 SimonQtWidgets[1031:41669] Cannot load library /Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib: (dlopen(/Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib, 133): Library not loaded: /usr/local/mysql/lib/libmysqlclient.20.dylib
          Referenced from: /Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib
          Reason: image not found)
        2018-10-11 08:28:13.255844+0100 SimonQtWidgets[1031:41669] QLibraryPrivate::loadPlugin failed on "/Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib" : "Cannot load library /Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib: (dlopen(/Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib, 133): Library not loaded: /usr/local/mysql/lib/libmysqlclient.20.dylib\n  Referenced from: /Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib\n  Reason: image not found)"
        2018-10-11 08:28:13.255
        859+0100 SimonQtWidgets[1031:41669] QSqlDatabase: QMYSQL driver not loaded
        2018-10-11 08:28:13.255885+0100 SimonQtWidgets[1031:41669] QSqlDatabase: available drivers: QSQLITE QMYSQL QMYSQL3 QPSQL QPSQL7
        
        jsulmJ Offline
        jsulmJ Offline
        jsulm
        Lifetime Qt Champion
        wrote on last edited by
        #29

        @SPlatten said in Qt5.11.2, QSqlDatabase, QMYSQL, Driver not loaded:

        Library not loaded: /usr/local/mysql/lib/libmysqlclient.20.dylib

        Do you have this lib in that location?

        https://forum.qt.io/topic/113070/qt-code-of-conduct

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        0
        • SPlattenS Offline
          SPlattenS Offline
          SPlatten
          wrote on last edited by
          #30

          @jsulm , No, I've no idea what this library is or where is comes from. The path /usr/local/mysql doesn't exist.

          Kind Regards,
          Sy

          jsulmJ 1 Reply Last reply
          0
          • SPlattenS SPlatten

            @jsulm , No, I've no idea what this library is or where is comes from. The path /usr/local/mysql doesn't exist.

            jsulmJ Offline
            jsulmJ Offline
            jsulm
            Lifetime Qt Champion
            wrote on last edited by
            #31

            @SPlatten This is the MySQL client library which is used by Qt to access MySQL databases. You need it if you want to use MySQL.

            https://forum.qt.io/topic/113070/qt-code-of-conduct

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            0
            • SPlattenS Offline
              SPlattenS Offline
              SPlatten
              wrote on last edited by
              #32

              @jsulm said in Qt5.11.2, QSqlDatabase, QMYSQL, Driver not loaded:

              libmysqlclient.20.dylib

              I've found what I think is the correct library on my system:

                  /usr/local/Cellar/mariadb/10.2.6/lib/libmariadb.dylib
              

              I then tried:

                  sudo ln -s /usr/local/Cellar/mariadb/10.2.6/lib/libmariadb.dylib /usr/local/lib/libmysqlclient.20.dylib
              

              Re-ran in debug and the problem has changed, looks like I'm using the wrong library now:

              2018-10-11 09:15:08.331712+0100 SimonQtWidgets[1644:135071] Got keys from plugin meta data ("QPSQL7", "QPSQL")
              2018-10-11 09:15:08.331726+0100 SimonQtWidgets[1644:135071] QFactoryLoader::QFactoryLoader() checking directory path "/Users/simonplatten/build-SimonQtWidgets-Desktop_Qt_5_11_2_clang_64bit-Debug/SimonQtWidgets.app/Contents/MacOS/sqldrivers" ...
              2018-10-11 09:15:08.347152+0100 SimonQtWidgets[1644:135071] Cannot load library /Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib: (dlopen(/Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib, 133): Library not loaded: /usr/local/mysql/lib/libmysqlclient.20.dylib
                Referenced from: /Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib
                Reason: Incompatible library version: libqsqlmysql.dylib requires version 20.0.0 or later, but libmysqlclient.20.dylib provides version 3.0.0)
              2018-10-11 09:15:08.347182+0100 SimonQtWidgets[1644:135071] QLibraryPrivate::loadPlugin failed on "/Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib" : "Cannot load library /Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib: (dlopen(/Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib, 133): Library not loaded: /usr/local/mysql/lib/libmysqlclient.20.dylib\n  Referenced from: /Users/sim
              onplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib\n  Reason: Incompatible library version: libqsqlmysql.dylib requires version 20.0.0 or later, but libmysqlclient.20.dylib provides version 3.0.0)"
              2018-10-11 09:15:08.347201+0100 SimonQtWidgets[1644:135071] QSqlDatabase: QMYSQL driver not loaded
              2018-10-11 09:15:08.347228+0100 SimonQtWidgets[1644:135071] QSqlDatabase: available drivers: QSQLITE QMYSQL QMYSQL3 QPSQL QPSQL7
              

              Kind Regards,
              Sy

              1 Reply Last reply
              0
              • SGaistS Offline
                SGaistS Offline
                SGaist
                Lifetime Qt Champion
                wrote on last edited by
                #33

                Don't use ln that won't help, use install_name_tool and update the path in libqsqlmysql.dylib to match what you have on your system.

                Interested in AI ? www.idiap.ch
                Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

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                0
                • SPlattenS Offline
                  SPlattenS Offline
                  SPlatten
                  wrote on last edited by SPlatten
                  #34

                  @SGaist, thank you, do you have an example? How do I achieve this?

                  Kind Regards,
                  Sy

                  1 Reply Last reply
                  0
                  • SGaistS Offline
                    SGaistS Offline
                    SGaist
                    Lifetime Qt Champion
                    wrote on last edited by
                    #35

                    Did you read the tool's help ?

                    install_name_tool -change /usr/local/mysql/lib/libmysqlclient.20.dylib /path/to/mariadb/libmariadbclient.X.dylib /Users/hasan/Qt5.9.1/5.9.1/clang_64/plugins/sqldrivers/libqsqlmysql.dylib

                    Note that MariaDB should be a drop-in replacement however I haven't tried to "re-link" to a library that has different name (just a different compatible version number) so you may have other surprises.

                    Interested in AI ? www.idiap.ch
                    Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                    1 Reply Last reply
                    1
                    • SPlattenS Offline
                      SPlattenS Offline
                      SPlatten
                      wrote on last edited by SPlatten
                      #36

                      @SPlatten said in Qt5.11.2, QSqlDatabase, QMYSQL, Driver not loaded:

                      2018-10-11 09:15:08.331712+0100 SimonQtWidgets[1644:135071] Got keys from plugin meta data ("QPSQL7", "QPSQL")
                      2018-10-11 09:15:08.331726+0100 SimonQtWidgets[1644:135071] QFactoryLoader::QFact

                      @SGaist

                      I'm struggling, the only libmariadbclient I can find on my entire system is:

                          /usr/local/Cellar/mariadb/10.2.6/lib/libmariadbclient.a
                      

                      Kind Regards,
                      Sy

                      1 Reply Last reply
                      0
                      • SGaistS Offline
                        SGaistS Offline
                        SGaist
                        Lifetime Qt Champion
                        wrote on last edited by SGaist
                        #37

                        Then that's something you have to check with the brew folks.

                        Interested in AI ? www.idiap.ch
                        Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                        1 Reply Last reply
                        0
                        • SPlattenS Offline
                          SPlattenS Offline
                          SPlatten
                          wrote on last edited by SPlatten
                          #38

                          @SGaist , I was looking for an .so library, I've now learnt that a .dylib is the mac os equivalent.

                          The database I'm using is MariaDB, I've just updated this using:

                           brew upgrade mariadb
                          

                          Then:

                          brew services restart mariadb
                          

                          This has added:

                          /usr/local/Cellar/mariadb/10.3.10/lib
                          

                          Containing:

                          -rwxr-xr-x  1 simonplatten  staff  1425020 13 Sep 05:40 libqsqlite.dylib
                          drwxr-xr-x  3 simonplatten  staff       96  4 Oct 13:26 libqsqlite.dylib.dSYM
                          -rwxr-xr-x  1 simonplatten  staff  1435972 13 Sep 05:38 libqsqlite_debug.dylib
                          drwxr-xr-x  3 simonplatten  staff       96  4 Oct 13:26 libqsqlite_debug.dylib.dSYM
                          -rwxr-xr-x  1 simonplatten  staff    79864 13 Sep 05:40 libqsqlmysql.dylib
                          drwxr-xr-x  3 simonplatten  staff       96  4 Oct 13:26 libqsqlmysql.dylib.dSYM
                          -rwxr-xr-x  1 simonplatten  staff   137448 13 Sep 05:38 libqsqlmysql_debug.dylib
                          drwxr-xr-x  3 simonplatten  staff       96  4 Oct 13:26 libqsqlmysql_debug.dylib.dSYM
                          -rwxr-xr-x  1 simonplatten  staff    88980 13 Sep 05:40 libqsqlpsql.dylib
                          drwxr-xr-x  3 simonplatten  staff       96  4 Oct 13:26 libqsqlpsql.dylib.dSYM
                          -rwxr-xr-x  1 simonplatten  staff   138612 13 Sep 05:38 libqsqlpsql_debug.dylib
                          drwxr-xr-x  3 simonplatten  staff       96  4 Oct 13:26 libqsqlpsql_debug.dylib.dSYM
                          

                          Looking at the debug output from the Application Output:

                          2018-10-12 02:33:13.197110+0100 SimonQtWidgets[6965:134266] Cannot load library /Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib: (dlopen(/Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib, 133): Library not loaded: /usr/local/mysql/lib/libmysqlclient.20.dylib
                            Referenced from: /Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib
                            Reason: image not found)
                          

                          Why is it trying to load libmysqlclient.20.dylib ?

                          The next line in the Application output:

                          2018-10-12 02:33:13.197133+0100 SimonQtWidgets[6965:134266] QLibraryPrivate::loadPlugin failed on "/Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib" : "Cannot load library /Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib: (dlopen(/Users/simonplatten/Qt/
                          

                          Then:

                          (dlopen(/Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib, 133): Library not loaded: /usr/local/mysql/lib/libmysqlclient.20.dylib\n  Referenced from: /Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib\n  Reason: image not found)"
                          2018-10-12 02:33:13.1
                          97150+0100 SimonQtWidgets[6965:134266] QSqlDatabase: QMYSQL driver not loaded
                          

                          Kind Regards,
                          Sy

                          1 Reply Last reply
                          0
                          • SPlattenS Offline
                            SPlattenS Offline
                            SPlatten
                            wrote on last edited by SPlatten
                            #39

                            @SPlatten said in Qt5.11.2, QSqlDatabase, QMYSQL, Driver not loaded:

                            libmysqlclient.20.dylib

                            @SGaist , I managed to progress the issue, this is what I did:

                            Manually create the required folder structure, from /usr/local:

                            sudo mkdir mysql
                            cd mysql
                            sudo mkdir lib
                            cd lib
                            

                            Then create a symbolic link to the required library:

                            sudo ln -s /usr/local/lib/libmysqlclient.dylib /usr/local/mysql/lib/libmysqlclient.20.dylib
                            

                            Now debugging the same project, the call to open still fails with:

                            2018-10-12 08:44:19.696706+0100 SimonQtWidgets[1253:117317] loaded library "/Users/simonplatten/Qt/5.11.2/clang_64/plugins/sqldrivers/libqsqlmysql.dylib"
                            2018-10-12 08:44:39.663805+0100 SimonQtWidgets[1253:117317] QSqlError("1130", "QMYSQL: Unable to connect", "Host '192.168.1.158' is not allowed to connect to this MariaDB server")
                            2018-10-12 08:44:40.409469+0100 SimonQtWidgets[1253:117317] Failed to connect.
                            

                            Now resolved, the issue here was that the call to setHostName was using the host name of the system, I changed this to localhost and now everything works.

                            Kind Regards,
                            Sy

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                            0
                            • SGaistS Offline
                              SGaistS Offline
                              SGaist
                              Lifetime Qt Champion
                              wrote on last edited by
                              #40

                              That shouldn't be necessary but at least it got you going further.

                              As for your second error, this is your database configuration you have to inspect.

                              Is it a remote machine ? If not then replace the host name with localhost and try again.

                              Interested in AI ? www.idiap.ch
                              Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                              1 Reply Last reply
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