Frzk/dummy

This minimal SailfishOS app tries to demonstrate the issues you get when using a QSqlTableModel and trying to remove items from it.

I was first surprised to discover that QSqlTableModel::removeRows doesn't call beginRemoveRows nor endRemoveRows.

I was also surprised to see that rowCount always return the right value when you add items the model, but that it doesn't when you remove items from the model !

Behavior is as follows :

• With model.editStrategy set to QSqlTableModel::OnManualSubmit :

  1. First case : without beginRemoveRows and endRemoveRows :

     • Expected : The database isn't updated unless you call submitAll.
     • Unexpected : The view isn't either : the deleted item remains visible in the SilicaListView with original values.
     • Unexpected : rowCount doesn't return the right value after a deletion.
     • Expected : Calling submitAll automatically calls select which resets the model : if there is a remorse running, the app crashes.

  2. Second case : with beginRemoveRows and endRemoveRows :

     • Expected : The database isn't updated until you call submitAll.
     • Unexpected : The last item of the SilicaListView is removed (!!), no matter what item you wanted to delete.
     • Unexpected : rowCount doesn't return the right value after a deletion.
     • Expected : Calling submitAll automatically calls select which resets the model : if there is a remorse running, the app crashes.

• With model.editStrategy set to QSqlTableModel::OnFieldChanged :

  1. First case : without beginRemoveRows and endRemoveRows :

     • Expected : The database is updated immediately.
     • Unexpected : The deleted item remains visible in the SilicaListView with undefined values unless you call select.
     • Unexpected : rowCount doesn't return the right value after a deletion.
     • Expected : Calling select refreshes the model : if there is a remorse running, the app crashes.

  2. Second case : with beginRemoveRows and endRemoveRows :

     • Expected : The database is updated immediately.
     • Unexpected : The deleted item remains visible in the SilicaListView with undefined values.
     • Unexpected : The last item of the SilicaListView is removed (!!), no matter what item you wanted to delete.
     • Unexpected : rowCount doesn't return the right value after a deletion.
     • Expected : Calling select refreshes the model : if there is a remorse running, the app crashes.

I've tried to keep the code easy to read and understand. Hope this will be useful.