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Forum Update on Monday, May 27th 2025

Can't write into database

Scheduled Pinned Locked Moved Unsolved General and Desktop
qsqldatabaseqsqlqml
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  • artwawA Offline
    artwawA Offline
    artwaw
    wrote on last edited by
    #2

    First things first, as you have - as far as I can tell - two separate problems here.
    First: with each press of the button you add a database connection (so the second time you press it you try to set new connection to db, so the old one is removed, so you get the info). Then each time you create table which might as well exist.
    To avoid that I'd suggest moving the addDatabase and table creation somewhere else, where it is called once. You can retrieve database with:

    auto db=QSqlDatabase::database();
    if (!db.isOpen()) {
    db.Open();
    }
    

    and then continue.
    Also, QSqlQuery returns lastError() and lastError().text() might be useful to debug the execution result.

    For more information please re-read.

    Kind Regards,
    Artur

    B 1 Reply Last reply
    1
    • artwawA artwaw

      First things first, as you have - as far as I can tell - two separate problems here.
      First: with each press of the button you add a database connection (so the second time you press it you try to set new connection to db, so the old one is removed, so you get the info). Then each time you create table which might as well exist.
      To avoid that I'd suggest moving the addDatabase and table creation somewhere else, where it is called once. You can retrieve database with:

      auto db=QSqlDatabase::database();
      if (!db.isOpen()) {
      db.Open();
      }
      

      and then continue.
      Also, QSqlQuery returns lastError() and lastError().text() might be useful to debug the execution result.

      B Offline
      B Offline
      Babs
      wrote on last edited by
      #3

      @artwaw thanks you. I moved my database and tableCreation in my main function. I assume that it's called only once then. It still doesn't work. By printing lastError().txt i get the following message:
      SqlQuery::prepare: database not open
      "Driver not loaded Driver not loaded"

      artwawA 1 Reply Last reply
      0
      • B Babs

        @artwaw thanks you. I moved my database and tableCreation in my main function. I assume that it's called only once then. It still doesn't work. By printing lastError().txt i get the following message:
        SqlQuery::prepare: database not open
        "Driver not loaded Driver not loaded"

        artwawA Offline
        artwawA Offline
        artwaw
        wrote on last edited by
        #4

        @Babs Ok. So now you can test db.open() - it returns a value. On false, error should be present in lastError().

        For more information please re-read.

        Kind Regards,
        Artur

        B 1 Reply Last reply
        0
        • artwawA artwaw

          @Babs Ok. So now you can test db.open() - it returns a value. On false, error should be present in lastError().

          B Offline
          B Offline
          Babs
          wrote on last edited by Babs
          #5

          @artwaw it returns false and the error driver not loaded. I do the verification:

                  if(!db.isOpen()){
                      db.open();
                      qDebug()<<db.lastError().text();
                  }
          
          artwawA 1 Reply Last reply
          0
          • B Babs

            @artwaw it returns false and the error driver not loaded. I do the verification:

                    if(!db.isOpen()){
                        db.open();
                        qDebug()<<db.lastError().text();
                    }
            
            artwawA Offline
            artwawA Offline
            artwaw
            wrote on last edited by
            #6

            @Babs Are you completely sure that addDatabase() has been called at any point before call do QSqlDatabase::database()?
            You could also test if driver is available by using QSqlDatabase::drivers() and other methods described in documentation.

            For more information please re-read.

            Kind Regards,
            Artur

            B 2 Replies Last reply
            0
            • artwawA artwaw

              @Babs Are you completely sure that addDatabase() has been called at any point before call do QSqlDatabase::database()?
              You could also test if driver is available by using QSqlDatabase::drivers() and other methods described in documentation.

              B Offline
              B Offline
              Babs
              wrote on last edited by
              #7

              @artwaw do i have to specify the connectionName when calling database() function?. Add data base in called in my main function before creation my engine.

              1 Reply Last reply
              0
              • artwawA artwaw

                @Babs Are you completely sure that addDatabase() has been called at any point before call do QSqlDatabase::database()?
                You could also test if driver is available by using QSqlDatabase::drivers() and other methods described in documentation.

                B Offline
                B Offline
                Babs
                wrote on last edited by
                #8

                @artwaw the driver for SQLite is indeed present.

                artwawA 1 Reply Last reply
                0
                • B Babs

                  @artwaw the driver for SQLite is indeed present.

                  artwawA Offline
                  artwawA Offline
                  artwaw
                  wrote on last edited by
                  #9

                  @Babs can you post your .pro files please?

                  For more information please re-read.

                  Kind Regards,
                  Artur

                  B 2 Replies Last reply
                  0
                  • artwawA artwaw

                    @Babs can you post your .pro files please?

                    B Offline
                    B Offline
                    Babs
                    wrote on last edited by
                    #10

                    @artwaw i'm working with QBS. When i don't specify the connectionName in addDataBase() function it open. I have the error "number of parameters incorrect". I think i don't have the good parameter types. I defined a QString as a TEXT is SQLite. Is it correct?

                    1 Reply Last reply
                    0
                    • artwawA artwaw

                      @Babs can you post your .pro files please?

                      B Offline
                      B Offline
                      Babs
                      wrote on last edited by
                      #11

                      @artwaw here is my QBS file

                      import qbs
                      
                      
                      
                      Project{
                          name: "PlanningModrian"
                      
                          Product{
                              files: [
                              ]
                              name: ( "modrian");
                              type: "application";
                              targetName: (project.targetPrefixTools + "modrian");
                              cpp.dynamicLibraries: {
                                  var ret = [];
                                  if (Qt.core.versionMinor < 4) { // NOTE : prior to Qt5.4 we had to link libGL manually
                                      ret.push ("GL");
                                  }
                                  return ret;
                              }
                      
                              cpp.cxxLanguageVersion: "c++14"
                              readonly property stringList qmlImportPaths : [sourceDirectory + "/import"]; // equivalent to QML_IMPORT_PATH += $$PWD/import
                      
                              Depends { name: "Qt.quick" }
                              Depends {
                                  name: "Qt";
                                  submodules: ["core", "gui", "qml", "quick","testlib","sql"];
                              }
                              Group{
                                  name: "C++ sources";
                                  files: [
                                      "planning.cpp",
                                      "main.cpp",
                                      "admin.cpp",
                                      "testPlanning.cpp",
                                      "user.cpp",
                                      "equipement.cpp",
                                      "equimenttablemodel.cpp",
                                      "palier.cpp",
                                      "paliermodel.cpp",
                                      "appwrapper.cpp",
                                  ]
                              }
                              Group {
                                  qbs.install: (product.type === "dynamiclibrary");
                                  fileTagsFilter: product.type;
                              }
                      
                              Group{
                                  name: "C++ headers";
                                  files: [
                                      "admin.h",
                                      "appwrapper.h",
                                      "datetimevalidator.cpp",
                                      "datetimevalidator.h",
                                      "equimenttablemodel.h",
                                      "manager.cpp",
                                      "manager.h",
                                      "paliermodel.h",
                                      "planning.h",
                                      "user.h",
                                      "equipement.h",
                                      "palier.h",
                                  ]
                              }
                              Group  {
                                  name: "QML files"
                                  files: [
                                      "DatePicker.qml",
                                      "DateUtils.js",
                                      "Planning.qml",
                                      "main.qml",
                                      "PagePlannification.qml",
                                      "qml.qrc",
                                  ]
                              }
                      
                              //Depends { name: (project.namePrefixBase + "utils"); }
                              Depends { name: "libqtqmltricks-qtsupermacros"; }
                              Depends { name: "libqtqmltricks-qtqmlmodels"; }
                              Depends { name: "libqtqmltricks-qtquickuielements"; }
                          }
                      }
                      
                      
                      artwawA B 2 Replies Last reply
                      0
                      • B Babs

                        @artwaw here is my QBS file

                        import qbs
                        
                        
                        
                        Project{
                            name: "PlanningModrian"
                        
                            Product{
                                files: [
                                ]
                                name: ( "modrian");
                                type: "application";
                                targetName: (project.targetPrefixTools + "modrian");
                                cpp.dynamicLibraries: {
                                    var ret = [];
                                    if (Qt.core.versionMinor < 4) { // NOTE : prior to Qt5.4 we had to link libGL manually
                                        ret.push ("GL");
                                    }
                                    return ret;
                                }
                        
                                cpp.cxxLanguageVersion: "c++14"
                                readonly property stringList qmlImportPaths : [sourceDirectory + "/import"]; // equivalent to QML_IMPORT_PATH += $$PWD/import
                        
                                Depends { name: "Qt.quick" }
                                Depends {
                                    name: "Qt";
                                    submodules: ["core", "gui", "qml", "quick","testlib","sql"];
                                }
                                Group{
                                    name: "C++ sources";
                                    files: [
                                        "planning.cpp",
                                        "main.cpp",
                                        "admin.cpp",
                                        "testPlanning.cpp",
                                        "user.cpp",
                                        "equipement.cpp",
                                        "equimenttablemodel.cpp",
                                        "palier.cpp",
                                        "paliermodel.cpp",
                                        "appwrapper.cpp",
                                    ]
                                }
                                Group {
                                    qbs.install: (product.type === "dynamiclibrary");
                                    fileTagsFilter: product.type;
                                }
                        
                                Group{
                                    name: "C++ headers";
                                    files: [
                                        "admin.h",
                                        "appwrapper.h",
                                        "datetimevalidator.cpp",
                                        "datetimevalidator.h",
                                        "equimenttablemodel.h",
                                        "manager.cpp",
                                        "manager.h",
                                        "paliermodel.h",
                                        "planning.h",
                                        "user.h",
                                        "equipement.h",
                                        "palier.h",
                                    ]
                                }
                                Group  {
                                    name: "QML files"
                                    files: [
                                        "DatePicker.qml",
                                        "DateUtils.js",
                                        "Planning.qml",
                                        "main.qml",
                                        "PagePlannification.qml",
                                        "qml.qrc",
                                    ]
                                }
                        
                                //Depends { name: (project.namePrefixBase + "utils"); }
                                Depends { name: "libqtqmltricks-qtsupermacros"; }
                                Depends { name: "libqtqmltricks-qtqmlmodels"; }
                                Depends { name: "libqtqmltricks-qtquickuielements"; }
                            }
                        }
                        
                        
                        artwawA Offline
                        artwawA Offline
                        artwaw
                        wrote on last edited by
                        #12

                        @Babs ups. I have literally zero experience with qbs...
                        I am afraid you'll have to wait for someone who knows something about it, I am sorry.

                        For more information please re-read.

                        Kind Regards,
                        Artur

                        1 Reply Last reply
                        0
                        • B Babs

                          @artwaw here is my QBS file

                          import qbs
                          
                          
                          
                          Project{
                              name: "PlanningModrian"
                          
                              Product{
                                  files: [
                                  ]
                                  name: ( "modrian");
                                  type: "application";
                                  targetName: (project.targetPrefixTools + "modrian");
                                  cpp.dynamicLibraries: {
                                      var ret = [];
                                      if (Qt.core.versionMinor < 4) { // NOTE : prior to Qt5.4 we had to link libGL manually
                                          ret.push ("GL");
                                      }
                                      return ret;
                                  }
                          
                                  cpp.cxxLanguageVersion: "c++14"
                                  readonly property stringList qmlImportPaths : [sourceDirectory + "/import"]; // equivalent to QML_IMPORT_PATH += $$PWD/import
                          
                                  Depends { name: "Qt.quick" }
                                  Depends {
                                      name: "Qt";
                                      submodules: ["core", "gui", "qml", "quick","testlib","sql"];
                                  }
                                  Group{
                                      name: "C++ sources";
                                      files: [
                                          "planning.cpp",
                                          "main.cpp",
                                          "admin.cpp",
                                          "testPlanning.cpp",
                                          "user.cpp",
                                          "equipement.cpp",
                                          "equimenttablemodel.cpp",
                                          "palier.cpp",
                                          "paliermodel.cpp",
                                          "appwrapper.cpp",
                                      ]
                                  }
                                  Group {
                                      qbs.install: (product.type === "dynamiclibrary");
                                      fileTagsFilter: product.type;
                                  }
                          
                                  Group{
                                      name: "C++ headers";
                                      files: [
                                          "admin.h",
                                          "appwrapper.h",
                                          "datetimevalidator.cpp",
                                          "datetimevalidator.h",
                                          "equimenttablemodel.h",
                                          "manager.cpp",
                                          "manager.h",
                                          "paliermodel.h",
                                          "planning.h",
                                          "user.h",
                                          "equipement.h",
                                          "palier.h",
                                      ]
                                  }
                                  Group  {
                                      name: "QML files"
                                      files: [
                                          "DatePicker.qml",
                                          "DateUtils.js",
                                          "Planning.qml",
                                          "main.qml",
                                          "PagePlannification.qml",
                                          "qml.qrc",
                                      ]
                                  }
                          
                                  //Depends { name: (project.namePrefixBase + "utils"); }
                                  Depends { name: "libqtqmltricks-qtsupermacros"; }
                                  Depends { name: "libqtqmltricks-qtqmlmodels"; }
                                  Depends { name: "libqtqmltricks-qtquickuielements"; }
                              }
                          }
                          
                          
                          B Offline
                          B Offline
                          Babs
                          wrote on last edited by
                          #13

                          I resolved my problem. I made an error in the type an name of one of the parameters. Thanks for your help @artwaw.

                          artwawA 1 Reply Last reply
                          1
                          • B Babs

                            I resolved my problem. I made an error in the type an name of one of the parameters. Thanks for your help @artwaw.

                            artwawA Offline
                            artwawA Offline
                            artwaw
                            wrote on last edited by
                            #14

                            @Babs Anytime.
                            Please don't forget to mark the thread as "solved".

                            For more information please re-read.

                            Kind Regards,
                            Artur

                            1 Reply Last reply
                            0

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