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QSqlQuery::prepare: database not open

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  • SGaistS SGaist

    Hi,

    Are you running phpmyadmin on the same machine as the MySQL server ?

    Are you running your application on the same machine as the server ?

    If no to the second question, then did you correctly configure your MySQL server to accept external connections ? And also don't forget to secure them.

    R Offline
    R Offline
    RekTek249
    wrote on last edited by
    #7

    @SGaist I'm hosting the sql server on a website. It's a hosting website so I guess it's a linux server ? I'm running phpmyadmin on my windows 10 computer.

    1 Reply Last reply
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    • SGaistS Offline
      SGaistS Offline
      SGaist
      Lifetime Qt Champion
      wrote on last edited by
      #8

      Then check that you are correctly using the same user name, password as you are using in PHPMyAdmin.

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

      R 1 Reply Last reply
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      • SGaistS SGaist

        Then check that you are correctly using the same user name, password as you are using in PHPMyAdmin.

        R Offline
        R Offline
        RekTek249
        wrote on last edited by
        #9

        @SGaist It is the correct one i checked that before asking it here...

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        • SGaistS Offline
          SGaistS Offline
          SGaist
          Lifetime Qt Champion
          wrote on last edited by
          #10

          What exact error message do you get from your QSqlDatabase object ?

          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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          • R RekTek249

            Hey, I started SQL today and I was wondering why it says db isn't open. Note: I had trouble with another error saying the driver wasn't found or something and I added a bunch of files to system PATH. Here is my code.

            void w::database(){
            QSqlDatabase db = QSqlDatabase::addDatabase("QMYSQL");
                db.setHostName("Host");
                db.setDatabaseName("Name");         /* In my real code, I set the real
                db.setUserName("Username");               stuff here */
                db.setPassword("Password");
            
                if (db.open())                                             
                {                                                                        
                    QMessageBox msgBox;                         
                    msgBox.setText("DB OPENED");          
                    msgBox.exec();
            
                }
            
            
                QSqlQuery query(db);
                query.prepare("INSERT INTO person (Username, Password, summ, Email) "  
                                  "VALUES (:user, :pass, :summ, :mail)");
                query.bindValue(":user", Username);          // I do have variables set earlier
                query.bindValue(":pass", Password);
                query.bindValue(":summ", summ);
                query.bindValue(":mail", Email);
                query.exec();
            
            }
            

            For some reasons, when I press the button (which launch this method) if I have the db.open part, It "doesn't respond". Help anyone... I searched on internet but didn't find anything that solved my problem...
            Thanks

            Taz742T Offline
            Taz742T Offline
            Taz742
            wrote on last edited by
            #11

            @RekTek249

                QSqlQuery query(db);
                query.prepare("INSERT INTO person (Username, Password, summ, Email) "  
                                  "VALUES (:user, :pass, :summ, :mail)");
                query.bindValue(":user", Username);          // I do have variables set earlier
                query.bindValue(":pass", Password);
                query.bindValue(":summ", summ);
                query.bindValue(":mail", Email);
                query.exec();
            

            The mistake is not giving you anything error?

            please #include "QSqlError" and

             if (db.open())                                             
                {                                                                        
                    QMessageBox msgBox;                         
                    msgBox.setText("DB OPENED");          
                    msgBox.exec();
            
                }
            else{
                   qDebug() << db.lastError()
             }
            

            By doing so we can understand what the problem is about anyway...

            Do what you want.

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            • R Offline
              R Offline
              RekTek249
              wrote on last edited by RekTek249
              #12

              @Taz742 QSqlError("2003", "QMYSQL: Unable to connect", "Can't connect to MySQL server on 'adress.here' (10060)")
              Is the error...

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              • SGaistS Offline
                SGaistS Offline
                SGaist
                Lifetime Qt Champion
                wrote on last edited by
                #13

                Did you check that the user you are using to connect to the database can be used for remote connections ?

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

                R 1 Reply Last reply
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                • SGaistS SGaist

                  Did you check that the user you are using to connect to the database can be used for remote connections ?

                  R Offline
                  R Offline
                  RekTek249
                  wrote on last edited by
                  #14

                  @SGaist It can.... What is the "2003" and 10060 meaning ? is 2003 the port ?

                  Taz742T 1 Reply Last reply
                  0
                  • R Offline
                    R Offline
                    RekTek249
                    wrote on last edited by
                    #15

                    I tried it on another server and it gives the following error..

                    QSqlError("2005", "QMYSQL: Unable to connect", "Unknown MySQL server host 'mysql.hostinger.fr' (0)")
                    QSqlQuery::prepare: database not open
                    
                    the_T 1 Reply Last reply
                    0
                    • R RekTek249

                      I tried it on another server and it gives the following error..

                      QSqlError("2005", "QMYSQL: Unable to connect", "Unknown MySQL server host 'mysql.hostinger.fr' (0)")
                      QSqlQuery::prepare: database not open
                      
                      the_T Offline
                      the_T Offline
                      the_
                      wrote on last edited by
                      #16

                      @RekTek249
                      Again: are you sure you are allowed to establish a remote connection to the database?

                      • check user permission
                      • check if port is correct
                      • check if port is reachable from remote

                      -- No support in PM --

                      1 Reply Last reply
                      2
                      • R RekTek249

                        @SGaist It can.... What is the "2003" and 10060 meaning ? is 2003 the port ?

                        Taz742T Offline
                        Taz742T Offline
                        Taz742
                        wrote on last edited by
                        #17

                        @RekTek249 said in QSqlQuery::prepare: database not open:

                        It can.... What is the "2003" and 10060 meaning ? is 2003 the port ?

                        2003 is not a port name, so let's say the title of the problem.

                        Do what you want.

                        the_T 1 Reply Last reply
                        0
                        • Taz742T Taz742

                          @RekTek249 said in QSqlQuery::prepare: database not open:

                          It can.... What is the "2003" and 10060 meaning ? is 2003 the port ?

                          2003 is not a port name, so let's say the title of the problem.

                          the_T Offline
                          the_T Offline
                          the_
                          wrote on last edited by
                          #18

                          @Taz742
                          It's not a "title", just an qt internal error number. Same with the other code that is a mysql internal error code

                          -- No support in PM --

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                          • SGaistS Offline
                            SGaistS Offline
                            SGaist
                            Lifetime Qt Champion
                            wrote on last edited by
                            #19

                            To add to @the_ : the error state that mysql.hostinger.fr is an unknown host. Looks like you are giving the wrong address.

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

                            R 1 Reply Last reply
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                            • SGaistS SGaist

                              To add to @the_ : the error state that mysql.hostinger.fr is an unknown host. Looks like you are giving the wrong address.

                              R Offline
                              R Offline
                              RekTek249
                              wrote on last edited by
                              #20

                              @SGaist When I go to the "remote mysql" part of the site, it gives an access host... do i gotta use this as the hostname ?

                              R 1 Reply Last reply
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                              • R RekTek249

                                @SGaist When I go to the "remote mysql" part of the site, it gives an access host... do i gotta use this as the hostname ?

                                R Offline
                                R Offline
                                RekTek249
                                wrote on last edited by RekTek249
                                #21

                                @RekTek249 If that's what i do, it gives that error:

                                QSqlError("1045", "QMYSQL: Unable to connect", "Access denied for user 'rektek_write'@'*ip here*.' (using password: YES)")
                                

                                If it's a permission problem, what do I need to do ? I have the insert one because that's the only thing I need to do...

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

                                  Is this user authorised to access the database from outside that machine ?

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

                                  R 1 Reply Last reply
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                                  • SGaistS SGaist

                                    Is this user authorised to access the database from outside that machine ?

                                    R Offline
                                    R Offline
                                    RekTek249
                                    wrote on last edited by
                                    #23

                                    @SGaist Well it's a website host.... They wouldn't allow you to create hosts that can only connect on that machine i guess.

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                                    • SGaistS Offline
                                      SGaistS Offline
                                      SGaist
                                      Lifetime Qt Champion
                                      wrote on last edited by
                                      #24

                                      That I don't know, you should ask them.

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

                                      R 1 Reply Last reply
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                                      • SGaistS SGaist

                                        That I don't know, you should ask them.

                                        R Offline
                                        R Offline
                                        RekTek249
                                        wrote on last edited by
                                        #25

                                        @SGaist Alright... I checked something and apparently for remote you need the user's ip. The control panel needs the ip so I guess I can't make this application public because they wont be able to access the database ?

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                                        • SGaistS Offline
                                          SGaistS Offline
                                          SGaist
                                          Lifetime Qt Champion
                                          wrote on last edited by
                                          #26

                                          Then implement a REST service to expose what you need for your application.

                                          What exactly are you trying to implement ? Because currently it seems you are trying to do server-side stuff from your application.

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

                                          R 1 Reply Last reply
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