Program crash when creating sqlite database

Babs

Hello,
I'm working on a QML application that need a datebase base. The problem is when i create my database in main.cpp the program crash.
Here is my code:

int main(int argc, char *argv[])
{
    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
    QGuiApplication app(argc, argv);
    AppWrapper wrapper;
    QSqlDatabase db = QSqlDatabase::addDatabase("QSQLITE");//not dbConnection
    db.setDatabaseName("C:/Users/a.diaw/Documents/sql/databases/db_modrian.sqllite");
    if(!db.open()){
        qDebug()<<"problem opening database";
    }
    /*QSqlQuery query;
    query.exec("create table person "
              "(id integer primary key, "
              "firstname varchar(20), "
              "lastname varchar(30), "
              "age integer)");*/

    if ( !wrapper.initialize())
        return -1;

    return app.exec();
}

JonB

@Babs said in Program crash when creating sqllite database:

the program crash

"Crash" in what way? System error message? (Or do you mean the db.open() just fails?) If it crashes, run from debugger and look at traceback?

Babs

@JonB when i comment the part of the code about the database creation my program lauch the application window without problem. When i don't it crash before the

return app.exec()

db.open() doesn't fail

JonB

@Babs
Then I don't know, as your scope seems OK. No idea what else your code might do (e.g. wrapper.initialize()). So as I said why don't you run from debugger and look at stack trace, that's what it's for instead of guessing? (Even putting in qDebug()s to show which statement it is/is not reaching is better than now.)

artwaw

Hi,
as @JonB said - run in debug. Try step-by-step execution to see where exactly does it fail and hopefully you'll see what's wrong.

Babs

@JonB the programm indeed crash in wrapper.initialize()
Here is the code:

bool AppWrapper::initialize()
{

    Planning *plan= new Planning(this);
    mModel.setDataSource(plan);
    registerQtQmlTricksUiElements (&mEngine);
    registerQtQmlTricksSmartDataModel (&mEngine);
    mEngine.rootContext()->setContextProperty("myModel",&mModel);
    qmlRegisterType<PalierModel>("TableModel",0,1,"TableModel");
    mEngine.rootContext()->setContextProperty("plan", plan);
    qmlRegisterType<DateTimeValidator>("my.components", 1, 0, "DateTimeValidator");
    mEngine.load(QUrl(QStringLiteral("qrc:/main.qml")));
    ```
if(mEngine.rootObjects().isEmpty()){
        return false;
    }

    else{
        return true;
    }

}

It crash when we get to the line

if(mEngine.rootObjects().isEmpty()){
        return false;
    }

Here is the error message
12:35:05: The process was ended forcefully.
12:35:05: C:\Users\a.diaw\Documents\build-PlanningModrian-Desktop_Qt_5_14_1_MinGW_64_bit-Debug\Debug\modrian.57fb0ae3\undefinedmodrian.exe crashed.

Babs

Thank you all i resolved my problem.

Pablo J. Rogina

@Babs said in Program crash when creating sqlite database:

Thank you all i resolved my problem.

would you mind sharing the solution? Thanks.

Babs

@Pablo-J-Rogina i resolved the problem by moving the database creation in wrapper.initialize(). I assume that it's all about events in Qt. I don't understand yet this mechanism may be any one can explain it?

Pablo J. Rogina

@Babs said in Program crash when creating sqlite database:

I don't understand yet this mechanism may be any one can explain it?

Please create a new post with this subject, so not to hijack this thread. Thanks.