Yeah. In fact I was doing a mistake with my tests 
The real problem is : I cannot display my item stored in my pouchDB collection. I use this plugin https://github.com/danielzen/ng-pouchdb.
When I launch the demo, my couchDB server works fine and the collection display works too.
But when I include the collection in a controller in my ionic app, the display doesn't work and I don't why 
Is anybody here already used this plugin?