QT QML OfflineDatabaseAPI

[bmn]

I'm currently creating a program similar to Are you smarter than a 5th grader, where questions should be randomly chosen by the program.

If ever I use the OfflineDatabaseAPI to store my questions, how do I save the database into a file where I can access it or how do I save the database so that when the application is installed to a mobile phone the database will still be accessible?

[raja26]

If you are using latest Qt Creator i.e. Qt SDK 1.2, you will see these lines in your project pro file.

# Add more folders to ship with the application, here
folder_01.source = qml/QtQuickDemo
folder_01.target = qml
DEPLOYMENTFOLDERS = folder_01

# Add more folders to ship with the application, here
folder_01.source = qml/QtQuickDemo
folder_01.target = qml
DEPLOYMENTFOLDERS = folder_01

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use this facility to package and export your database files..

Else:
Create a database file during the first startup of the application.. And if the database is already present then do nothing..

This method is quite unwanted and indirect..

[bmn]

Hello,

Yes, my .pro file looks like that. However, I really don't have any knowledge on how to package/export database files. I don't even know where the database file is

[bmn]

Okay, so managed to stumble upon this.

http://developer.qt.nokia.com/forums/viewthread/2093

Basically, it helped out a lot. Although I have some questions for you pro's.

1. The dude who made the thread in that link stated that he created three files.

1. Qt.md5(“mydb_name”).ini
2. Qt.md5(“mydb_name”).sqlite
3. Qt.md5(“mydb_name”) folder

1. Qt.md5(“mydb_name”).ini
2. Qt.md5(“mydb_name”).sqlite
3. Qt.md5(“mydb_name”) folder

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I saw the .ini and the .sqlite file. But I didn't see that folder. Is that even required? And where do you declare these Qt.md5(“mydb_name”).ini? Inside your .cpp?

2. I did exactly what he did

QmlApplicationViewer viewer;
    viewer.engine()->setOfflineStoragePath(QString(customPath));

QmlApplicationViewer viewer;
    viewer.engine()->setOfflineStoragePath(QString(customPath));

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where my custom path is set to "qml/OfflineStorage"
I created that qml/OfflineStorage path manually by navigating to the project folder and just creating a new folder, renaming it OfflineStorage and there's where I copied and pasted the .ini and .sqlite files I found on the default location. Is that right?

Here's the structure of my project:

\qml
 \Projectproj
   \main.qml
   \data.txt
 \OfflineStorage
   \Databases
    \9a41722cf143cae53004c21c7ec7b42f.ini
    \9a41722cf143cae53004c21c7ec7b42f.sql

\qml
 \Projectproj
   \main.qml
   \data.txt
 \OfflineStorage
   \Databases
    \9a41722cf143cae53004c21c7ec7b42f.ini
    \9a41722cf143cae53004c21c7ec7b42f.sql

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I also made sure that my qrc file was updated.

<!DOCTYPE RCC><RCC version="1.0">
 <qresource>
     <file>qml/Projectproj/data.txt</file>
     <file>qml/OfflineStorage/Databases/9a41722cf143cae53004c21c7ec7b42f.ini</file>
     <file>qml/OfflineStorage/Databases/9a41722cf143cae53004c21c7ec7b42f.sqlite</file>
 </qresource>
 </RCC>

<!DOCTYPE RCC><RCC version="1.0">
 <qresource>
     <file>qml/Projectproj/data.txt</file>
     <file>qml/OfflineStorage/Databases/9a41722cf143cae53004c21c7ec7b42f.ini</file>
     <file>qml/OfflineStorage/Databases/9a41722cf143cae53004c21c7ec7b42f.sqlite</file>
 </qresource>
 </RCC>

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Is that right? Do I include the Databases folder in the filepath?

And when I ran the application, it didn't read the database stored in the default location (C:/Users/...) since i set the custom path to qml/OfflineStorage

Here's my main.cpp

QApplication app(argc, argv);
QDeclarativeEngine engine;
    QString customPath = "qml/OfflineStorage";
 QmlApplicationViewer viewer;
    viewer.engine()->setOfflineStoragePath(QString(customPath));
    viewer.setOrientation(QmlApplicationViewer::ScreenOrientationLockPortrait);
    viewer.setMainQmlFile(QLatin1String("qml/Projectproj/main.qml"));
    viewer.showExpanded();
    return app.exec();

QApplication app(argc, argv);
QDeclarativeEngine engine;
    QString customPath = "qml/OfflineStorage";
 QmlApplicationViewer viewer;
    viewer.engine()->setOfflineStoragePath(QString(customPath));
    viewer.setOrientation(QmlApplicationViewer::ScreenOrientationLockPortrait);
    viewer.setMainQmlFile(QLatin1String("qml/Projectproj/main.qml"));
    viewer.showExpanded();
    return app.exec();

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I wanna know what I'm doing wrong.

EDIT:

Well, I finally got it to work. The database opens. ALTHOUGH, how come I can't SAVE any data to my database?? When I use the default path -> C:/Users... etc, and I try to INSERT, it works. But when I set the customOfflineStoragePath, it does INSERT yes, but when I close the application and run it again, the database didn't change at all. How come?

[bmn]

Well, I finally got it to work. The database opens. ALTHOUGH, how come I can't SAVE any data to my database?? When I use the default path -> C:/Users... etc, and I try to INSERT, it works. But when I set the customOfflineStoragePath, it does INSERT yes, but when I close the application and run it again, the database didn't change at all. How come?

[wysota]

Because resource files are read-only. Stop shooting blind and start reading the documentation instead of gathering incoherent code snippets from all over the web trying to stitch them all toghether to complete your school assignment.