Skip to content
  • Categories
  • Recent
  • Tags
  • Popular
  • Users
  • Groups
  • Search
  • Get Qt Extensions
  • Unsolved
Collapse
Brand Logo
  1. Home
  2. Qt Development
  3. General and Desktop
  4. QSqlQuery::prepare: database not open
Forum Updated to NodeBB v4.3 + New Features

QSqlQuery::prepare: database not open

Scheduled Pinned Locked Moved Unsolved General and Desktop
30 Posts 6 Posters 17.1k Views 3 Watching
  • Oldest to Newest
  • Newest to Oldest
  • Most Votes
Reply
  • Reply as topic
Log in to reply
This topic has been deleted. Only users with topic management privileges can see it.
  • 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

    1 Reply Last reply
    0
    • 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.

      1 Reply Last reply
      0
      • 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...

        1 Reply Last reply
        0
        • 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 --

                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 --

                    1 Reply Last reply
                    0
                    • 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
                      0
                      • 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
                        0
                        • 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...

                          1 Reply Last reply
                          0
                          • 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
                            0
                            • 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.

                              1 Reply Last reply
                              0
                              • 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
                                0
                                • 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 ?

                                  1 Reply Last reply
                                  0
                                  • 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
                                    0
                                    • SGaistS SGaist

                                      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.

                                      R Offline
                                      R Offline
                                      RekTek249
                                      wrote on last edited by
                                      #27

                                      @SGaist I just need to store (INSERT) things in a database... And what is a REST ?

                                      the_T jsulmJ 2 Replies Last reply
                                      0
                                      • R RekTek249

                                        @SGaist I just need to store (INSERT) things in a database... And what is a REST ?

                                        the_T Offline
                                        the_T Offline
                                        the_
                                        wrote on last edited by
                                        #28

                                        @RekTek249
                                        See https://www.tutorialspoint.com/restful/

                                        -- No support in PM --

                                        1 Reply Last reply
                                        0
                                        • R RekTek249

                                          @SGaist I just need to store (INSERT) things in a database... And what is a REST ?

                                          jsulmJ Offline
                                          jsulmJ Offline
                                          jsulm
                                          Lifetime Qt Champion
                                          wrote on last edited by
                                          #29

                                          @RekTek249 Yes, you should implement a REST interface - exposing a SQL database to the public internet isn't a good idea.

                                          https://forum.qt.io/topic/113070/qt-code-of-conduct

                                          1 Reply Last reply
                                          0

                                          • Login

                                          • Login or register to search.
                                          • First post
                                            Last post
                                          0
                                          • Categories
                                          • Recent
                                          • Tags
                                          • Popular
                                          • Users
                                          • Groups
                                          • Search
                                          • Get Qt Extensions
                                          • Unsolved