node.js - One-To-One relationship with mongoose? -

i aware of how set 1 many relationship between mongoose entities, following type of code :

friends: [{type: objectid, ref: 'user'}] 

but if want have one-to-one relationship - such client user related to?

first of all, there huge difference between relationships in mongodb , in sql based datastores (you need clear get-go).

relationships in mongodb representations of related data. there no mechanism maintains integrity of these relationships.

what mongoose refs use field having ref option query _id field of documents in referenced collection. used operations populate (which internally calls findbyid queries on target collection , replaces referenced field documents).

this being cleared, can store 1 or many ids referenced collection in field, creating one-to-one or one-to-many "relationships".

so, store single id referenced collection, syntax be:

client: {type: mongoose.schema.types.objectid, ref: 'client'}  //no arrays, want store single id only. 

in same way, can store many ids referenced collection so:

friends: [{type: mongoose.schema.types.objectid, ref: 'user'}] //the array stores multiple ids, creating one-to-many "relationship" 

edit:

make sure have required mongoose module @ beginning.

var mongoose = require('mongoose');