From KDE Community Wiki

Android assets

Android assets are read-only arbitrary files bundled in their raw form into your package.Necessitas project provides seamless integration with android assets, meaning that you can access any asset files as you access any ordinary files.

Sqlite file seems to need write access, even if the db is not modified, so they will not work as assets file .

Deploy assets

Before accessing an asset we need to deploy it.

# assuming you want to deploy qml/foo/main.qml file, you need to add the flowing lines to your .pro/.pri file(s)
android { #define an android block
    deployment.path=/assets/qml/foo #all assets must go to "/assets" folder of your android package
} else : maemo5 { #other platforms
INSTALLS += deployment

Access assets

QmlApplicationViewer * m_qmlAppViewer;

QFile file( "assets:/qml/foo/main.qml" ); // to open a file just use its path and add *assets:/* prefix

// do whatever you want with file