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QSqlQuery::prepare: database not open

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  • jsulmJ jsulm

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

    "doesn't respond"

    is the host reachable? Did you try to connect to the server using MySQL client?

    R Offline
    R Offline
    RekTek249
    wrote on last edited by
    #5

    @jsulm It works with phpmyadmin... It doesn't respond for like 30sec and then if I wait it sends the "database not open"message in the output

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    • SGaistS Offline
      SGaistS Offline
      SGaist
      Lifetime Qt Champion
      wrote on last edited by
      #6

      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.

      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
      1
      • 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.

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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

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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
                    1
                    • 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 --

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                          • 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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