Cannot overwrite `Kitten` model once compiled - node.js

Question

I've run into an issue with the Mongoose Getting Started guide.
I have MongoDB running and everything is working perfectly until I add the last line:
Kitten.find({ name: /^Fluff/ }, callback)
When I node server.js I get this error:
OverwriteModelError: Cannot overwrite Kitten model once compiled.
Here's the full error and my server.js.
Any idea what I'm doing wrong?
P.S. I'm running node 10.26, npm 1.4.13, express 4.4.3 & mongoose 3.8.12 on OS X 10.9.3.

Answer 1

You get the error because callback in Kitten.find({ name: /^Fluff/ }, callback) calls var Kitten = mongoose.model('Kitten', kittySchema); again. Change
Kitten.find({ name: /^Fluff/ }, callback)
to something like:
Kitten.find({ name: /^Fluff/ }, function(err, kittens) {
});
It doesn't make sense to call the callback function again.

Answer 2

I thought this could be useful to someone else who tries it...
I started looking into mongoose and tried Getting Started guide. I don't see the above error happening where it was reported. However, I did see it intermittently. If it happens, follow #3 below. Here are my observations:
Issue#1. If I copy paste the whole code I see an issue with "I don't have a name" as the single quote in don't is not escaped.
Solution#1. I tried to escape with \ and \\ but it didn't work. Google search didn't help. After some research I found that it is forgiving for single quotes outside the function. But, inside the function it won't work. So, I defined a variable outside the function. Probably better to define strings in a separate document for localization anyways. Above all, it works. :)
Issue#2. I see the issue at
fluffy.speak();
TypeError: fluffy.speak is not a function
Here since the first 'mongoose.model(...)' doesn't have this method, adding it later and re-running 'mongoose.model(...)' will not help.
Solution#2. Comment the first 'mongoose.model(...)'
Issue#3. When I copy paste the code from the web site, it is causing weird errors.
Solution#3. Just deleted all the tabs and empty spaces at the end of lines in a Notepad++. That took care of it.
Here is the code that worked for me (Needless to say, if it doesn't work, please copy paste first in notepad):
var mongoose = require('mongoose');
mongoose.connect('mongodb://localhost/test');
var db = mongoose.connection;
db.on('error', console.error.bind(console, 'connection.error:'));
db.once('open', function(callback) {
//yay!
});
var kittySchema = mongoose.Schema({
name: String
});
//var Kitten = mongoose.model('Kitten', kittySchema);
//var silence = new Kitten({ name: 'Silence' });
//console.log(silence.name);
//console.log(silence);
var noname = "I don't have a name";
kittySchema.methods.speak = function () {
var greeting = this.name
? "Meow name is " + this.name
: noname;
console.log(greeting);
}
var Kitten = mongoose.model('Kitten', kittySchema);
var fluffy = new Kitten({ name : 'fluffy' });
fluffy.speak();