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Connect to MYSQL failed in Qt

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qt6c++mysqlmysql server
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  • E ELEMENTICY

    @SGaist
    current code:

    win32:CONFIG(release, debug|release): LIBS += -L$$PWD/lib/libmysql
    else:win32:CONFIG(debug, debug|release): LIBS += -L$$PWD/lib/libmysqld
    else:unix: LIBS += -L$$PWD/lib/libmysql
    

    idk if i misunderstanded what u mean,but it still give error ;/
    or u mean i have to remove that -L

    SGaistS Offline
    SGaistS Offline
    SGaist
    Lifetime Qt Champion
    wrote on last edited by
    #21

    @ELEMENTICY said in Connect to MYSQL failed in Qt:

    @SGaist
    current code:

    win32:CONFIG(release, debug|release): LIBS += -L$$PWD/lib/libmysql
    else:win32:CONFIG(debug, debug|release): LIBS += -L$$PWD/lib/libmysqld
    else:unix: LIBS += -L$$PWD/lib/libmysql
    

    idk if i misunderstanded what u mean,but it still give error ;/
    or u mean i have to remove that -L

    You have to understand what -L and -l each do. I have already explained that before. So please re-read the corresponding answers.

    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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    • E ELEMENTICY

      @SGaist and yea i dont know if its because im working on a android app,so it doesnt work

      SGaistS Offline
      SGaistS Offline
      SGaist
      Lifetime Qt Champion
      wrote on last edited by
      #22

      @ELEMENTICY said in Connect to MYSQL failed in Qt:

      @SGaist and yea i dont know if its because im working on a android app,so it doesnt work

      Oracle does not provide pre-built binaries for Android.

      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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      • E Offline
        E Offline
        ELEMENTICY
        wrote on last edited by ELEMENTICY
        #23

        @SGaist dude,im so tired...
        Can you pleaseee write the 3 lines of code for me?
        Please... i hope after you see this message,you wont just ignore and think i never hard work on it..But im tired for just add a simple library already...
        It will be the BEST help for me

        My current code...

        win32:CONFIG(release, debug|release): LIBS += $$PWD/lib/ -llibmysql
        else:win32:CONFIG(debug, debug|release): LIBS += $$PWD/lib/ -llibmysqld
        else:unix: LIBS += $$PWD/lib/ -llibmysql
        

        Error:
        :-1: error: error: cannot open C:/Users/ELEMENT/Documents/PosSystem/Pos/lib/: Permission denied
        I opened QT Creator with Administrator,still same...

        I also tried..

        win32:CONFIG(release, debug|release): LIBS += $$PWD/lib/libmysql
        else:win32:CONFIG(debug, debug|release): LIBS += $$PWD/lib/libmysqld
        else:unix: LIBS += $$PWD/lib/libmysql
        

        Error:
        :-1: error: no such file or directory: 'C:/Users/ELEMENT/Documents/PosSystem/Pos/lib/libmysql' clang++: error: no such file or directory: 'C:/Users/ELEMENT/Documents/PosSystem/Pos/lib/libmysql' make: *** [Makefile:79: libPos_x86_64.so] Error 1
        Seems like that one is the wrong way to do without adding -l

        appreciate it...

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        • E Offline
          E Offline
          ELEMENTICY
          wrote on last edited by
          #24

          @SGaist I removed:

          win32:CONFIG(release, debug|release): LIBS += $$PWD/lib/ -llibmysql
          else:win32:CONFIG(debug, debug|release): LIBS += $$PWD/lib/ -llibmysqld
          else:unix: LIBS += $$PWD/lib/ -llibmysql
          

          And tried only

          LIBS += -L"lib" -llibmysql
          

          Still error:
          :-1: error: error: cannot find -llibmysql

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          • SGaistS Offline
            SGaistS Offline
            SGaist
            Lifetime Qt Champion
            wrote on last edited by
            #25

            "Drop the lib prefix": -lmysql

            To repeat myself: Oracle does not provide pre-built binaries for Android.

            Also, @Christian-Ehrlicher already asked you several times: what exact error did you get with the QtSql module ?

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

            E 1 Reply Last reply
            1
            • SGaistS SGaist

              "Drop the lib prefix": -lmysql

              To repeat myself: Oracle does not provide pre-built binaries for Android.

              Also, @Christian-Ehrlicher already asked you several times: what exact error did you get with the QtSql module ?

              E Offline
              E Offline
              ELEMENTICY
              wrote on last edited by ELEMENTICY
              #26

              @SGaist ok its weird,it now dont give any error.But its EXCELENT!
              But it unable to connect to Server
              My code:

              QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL");
                      db.setHostName("localhost");
                      db.setDatabaseName("pos");
                      db.setUserName("root");
              
                      if (!db.open()){
                          ui->error->setText("Oops,Unable to connect to Server!Please contact your Administrator for help.");
                      }
              

              Includes:

              #include <QtSql/QSql>
              #include <QtSql/QSqlDatabase>
              #include <QtSql/QSqlDriver>
              #include <QtSql/QSqlQuery>
              

              and i also added sql to Qt in Profile

              QT       += core gui sql
              
              E 1 Reply Last reply
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              • E ELEMENTICY

                @SGaist ok its weird,it now dont give any error.But its EXCELENT!
                But it unable to connect to Server
                My code:

                QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL");
                        db.setHostName("localhost");
                        db.setDatabaseName("pos");
                        db.setUserName("root");
                
                        if (!db.open()){
                            ui->error->setText("Oops,Unable to connect to Server!Please contact your Administrator for help.");
                        }
                

                Includes:

                #include <QtSql/QSql>
                #include <QtSql/QSqlDatabase>
                #include <QtSql/QSqlDriver>
                #include <QtSql/QSqlQuery>
                

                and i also added sql to Qt in Profile

                QT       += core gui sql
                
                E Offline
                E Offline
                ELEMENTICY
                wrote on last edited by
                #27

                @ELEMENTICY im sure i entered correct server info

                JonBJ 1 Reply Last reply
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                • E ELEMENTICY

                  @ELEMENTICY im sure i entered correct server info

                  JonBJ Offline
                  JonBJ Offline
                  JonB
                  wrote on last edited by JonB
                  #28

                  @ELEMENTICY
                  So your root user has no password to connect to MySQL?

                  If db.open() fails, why don't you print out db.lastError() into your error message?

                  E 1 Reply Last reply
                  0
                  • SGaistS Offline
                    SGaistS Offline
                    SGaist
                    Lifetime Qt Champion
                    wrote on last edited by
                    #29

                    Do you have a run time warning stating that the plugin cannot be loaded ?

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

                    E 1 Reply Last reply
                    0
                    • SGaistS SGaist

                      Do you have a run time warning stating that the plugin cannot be loaded ?

                      E Offline
                      E Offline
                      ELEMENTICY
                      wrote on last edited by
                      #30

                      @SGaist yes there is

                      SGaistS 1 Reply Last reply
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                      • JonBJ JonB

                        @ELEMENTICY
                        So your root user has no password to connect to MySQL?

                        If db.open() fails, why don't you print out db.lastError() into your error message?

                        E Offline
                        E Offline
                        ELEMENTICY
                        wrote on last edited by
                        #31

                        @JonB no password,only root

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                        • E ELEMENTICY

                          @SGaist yes there is

                          SGaistS Offline
                          SGaistS Offline
                          SGaist
                          Lifetime Qt Champion
                          wrote on last edited by
                          #32

                          @ELEMENTICY said in Connect to MYSQL failed in Qt:

                          @SGaist yes there is

                          Then build the plugin following the instructions from the
                          documentation.

                          As I already noted: there's no prebuilt Oracle MySQL library for Androïd. You will have to build the MariaDB libraries and then the plugin for that platform.

                          As a side note: if you intend for your application to access that database through internet, you should reconsider that. It's a really bad idea to put a database in front of internet.

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

                          E 1 Reply Last reply
                          1
                          • SGaistS SGaist

                            @ELEMENTICY said in Connect to MYSQL failed in Qt:

                            @SGaist yes there is

                            Then build the plugin following the instructions from the
                            documentation.

                            As I already noted: there's no prebuilt Oracle MySQL library for Androïd. You will have to build the MariaDB libraries and then the plugin for that platform.

                            As a side note: if you intend for your application to access that database through internet, you should reconsider that. It's a really bad idea to put a database in front of internet.

                            E Offline
                            E Offline
                            ELEMENTICY
                            wrote on last edited by
                            #33

                            @SGaist ok lemme try,if i understand what documentation say lol

                            1 Reply Last reply
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