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Connect to MYSQL failed in Qt

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qt6c++mysqlmysql server
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  • E ELEMENTICY

    @SGaist my current profile code:

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

    documentation:

    LIBS += -L"3rdparty/CatWhisperer/lib" -lCatWhisperer
    

    i got this error:
    :-1: error: error: cannot find -llibmysql

    proof that path exists:
    Screenshot 2021-05-07 191143.png

    SGaistS Offline
    SGaistS Offline
    SGaist
    Lifetime Qt Champion
    wrote on last edited by
    #18

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

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

    E 2 Replies Last reply
    0
    • SGaistS SGaist

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

      E Offline
      E Offline
      ELEMENTICY
      wrote on last edited by
      #19

      @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 1 Reply Last reply
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      • SGaistS SGaist

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

        E Offline
        E Offline
        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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            • 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...

              1 Reply Last reply
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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

                1 Reply Last reply
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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
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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 ?

                    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
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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

                          E 1 Reply Last reply
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                          • 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

                              1 Reply Last reply
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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
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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.

                                  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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