[TYPO3-mvc] Repository in CommandController class not working properly

[Klaus Hörmann]

I use a CommandController to create a Scheduled Task for importing data.
The CommandController reads a CSV file, and then imports these to the database.
To remove all the current entries on the database, I tried to use

$myRepository->deleteAll();

But this wont work. Also

$myRepository->findAll();

doesnt work. It seems to me that all functions needing the "storagePid" set dont work, because findByUid($uid) works.
I configured the CommandController using TypoScript:

module.my_extension  < plugin.my_extension

I configured the plugin.my_extension with the persistence-storagePid node. The frontend works perfectly.

As I said it seems to me, that the module.my_extension.persistence.storagePid ist not properly configured in use with the CommandController. 

Can you see the error? Does this work with your extensions?
Where is my mistake? Do I need to configure anything?

Thanks
Klaus