node.js - How query API to get all the data for third level of path? -

this current schema have:

var schema = mongoose.schema;      var providerschema = new schema({         name: string,         abbreviated: string,         services: array,         locations: array,         description: string,         url: string,         upvotes:{type:number, default:0},         createdon: { type: date, default: date.now},         posts:[{ type: mongoose.schema.types.objectid, ref: 'post' }]     }); 

this post schema:

var postschema = new mongoose.schema({      title: string,      body: string,      upvotes: {type: number, default:0},      author: string,      provider: { type: mongoose.schema.types.objectid, ref: 'provider' },      comments:[{ type: mongoose.schema.types.objectid, ref: 'comment' }]  }); 

i populated post before:

router.get('/providers/:provider', function(req, res) {     req.provider.populate('posts', function(err, provider) {         res.json(provider);     }); }); 

and have in api:

router.get('/providers/:provider/posts', function(req, res) {     post.find(function(err, post){         if(err){ return next(err); }         res.json(post);     }); }); 

i write query in api query posts 1 provider. router.get not working , give me wrong answer.please if can me change query correct one. appreciated.

given schema , route assume have model called provider uses schema shown , :provider in url id requested provider. if use findbyid. also, since using array of references need populate them if want other ids:

router.get('/providers/:provider/posts', function(req, res) {   provider.findbyid(req.params.provider).select('posts').populate('posts').exec(function(err, provider) {     if(err){ return next(err); }     res.json(provider.posts);   }); }); 

otherwise if trying use post model need show schema.

update: using post model:

router.get('/providers/:provider/posts', function(req, res) {   post.find({provider: req.params.provider}, function(err, posts) {     if(err){ return next(err); }     res.json(posts);   }); });