Query firestore database for document id

Question

I want to query a firestore database for document id. Currently I have the following code:

db.collection('books').where('id', '==', 'fK3ddutEpD2qQqRMXNW5').get()

I don't get a result. But when I query for a different field it works:

db.collection('books').where('genre', '==', 'biography').get()

How is the name of the document id called?

Answer 1

I am a bit late, but there is actually a way to do this

db.collection('books').where(firebase.firestore.FieldPath.documentId(), '==', 'fK3ddutEpD2qQqRMXNW5').get()

This might be useful when you're dealing with firebase security rules and only want to query for the records you're allowed to access.