Error: "The 2nd parameter to mongoose.model() should be a schema or a POJO" after upgrading mongoose (discriminator related)

[antonioaltamura]

I'm not sure what's the problem, after upgrading mongoose I get the error in title at the row
var doc = mongoose.model('doc',docSchema);

The entire code

var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var caseNote = mongoose.model('caseNote');
var ObjectId=mongoose.Schema.Types.ObjectId;
var models = require('./');
var autopopulate = require('mongoose-autopopulate');

var docSchema_raw = new Schema({
    decidingBody:{type:String},
},{discriminatorKey : '_type'});

var docSchema = caseNote.discriminator('doc',  docSchema_raw);

var doc = mongoose.model('doc',docSchema);

exports.docSchema = docSchema;
module.exports = doc;

[adeelhussain]

@antonioaltamura why you are registering your doc model again?
try this.

var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var caseNote = mongoose.model('caseNote');
var ObjectId=mongoose.Schema.Types.ObjectId;
var models = require('./');
var autopopulate = require('mongoose-autopopulate');

var docSchema_raw = new Schema({
    decidingBody:{type:String},
},{discriminatorKey : '_type'});

var docSchema = caseNote.discriminator('doc',  docSchema_raw);

var doc = mongoose.model('doc');

exports.docSchema = docSchema;
module.exports = doc;

[antonioaltamura]

I'm sorry, I don't get what exactly means
var doc = mongoose.model('doc');

which schema am I defining as 'linked' to the model doc?

[adeelhussain]

Did you try to run my block of code?

[vkarpov15]

Why are you passing a model as the second parameter to mongoose.model()? That's not right. I'd imagine you just want to export docSchema, which is misleadingly named because it isn't a schema, it's actually a model.

[antonioaltamura]

So the right way to register doc as inherited model of the model caseNote is simply
var docSchema = caseNote.discriminator('doc', docSchema_raw); var doc = mongoose.model('doc');

just to be sure :)

[adeelhussain]

Exactly :)

[vkarpov15]

I think you're conflating documents and models. mongoose.model() returns a model, and then new MyModel() gives you a document.

[antonioaltamura]

There is no new Model here :)
I'm in doubt how the doc model is defined by the docSchema using @adeelhussain (working) code :)
I guess I should rewatch discriminator docs.

[Partho-FRz]

var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var caseNote = mongoose.model('caseNote');
var ObjectId=mongoose.Schema.Types.ObjectId;
var models = require('./');
var autopopulate = require('mongoose-autopopulate');

var docSchema = new mongoose.Schema({
decidingBody:{type:String},
},{discriminatorKey : '_type'});

var doc = mongoose.model('doc',docSchema);

exports.docSchema = docSchema;
module.exports = doc;

//this should for You :)

[bvedad]

Error occurs because discriminator method returns model object but mongoose.model method expects schema. This should be solved with:
var docSchema = caseNote.discriminator('doc', docSchema_raw);
var doc = mongoose.model('doc',docSchema.scheme);