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Connect to MYSQL failed in Qt

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qt6c++mysqlmysql server
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  • SGaistS SGaist

    @ELEMENTICY did you read what I wrote ? No "lib" prefix.

    E Offline
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    ELEMENTICY
    wrote on last edited by
    #20

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

    SGaistS 1 Reply Last reply
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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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          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
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            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

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              • 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 ?

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                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
                
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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
                  
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                  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 Online
                    JonBJ Online
                    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?

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                    • 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

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                      • SGaistS SGaist

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

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                        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?

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                          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

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                            • 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.

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                              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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