Use CouchDB-joins to manage foreign documents

Ionic Framework ionic-v3
1

Hi, I use couchDB for local storage,

Problem:
in first step, I used foreign_key to join my documents (my databases), example:
“Customer”:{ “_id”:"…",
…,“c_fk_address_id” :11}
“Address”:{"_id":11,…}

But with this solution, I have encountered problems in call Promise into *ngFor loop ( get address of each Customer in list)

So, the second solution, is to use:
“Customer”:{ “_id”:"…",
…,“c_address” :{"_id":11,…} // all object
}
“Address”:{"_id":11,…}

But, I have to change them manually (on update or delete)

Questions:
1- are CouchDB-joins a solution of my problem?
2- if yes, how can I add $doctype in my models (interface)?

THANK YOU!