Creating a collection schema in a mongolab mongodb database from node.js
You must insert a document first. Schemas are not explicitly defined in mongodb. Once you insert a document, the collection will automatically be created and you will see it in the mongolab console.
Example from http://mongoosejs.com/
var mongoose = require('mongoose');
var db = mongoose.createConnection('localhost', 'test');
var schema = mongoose.Schema({ name: 'string' });
var Cat = db.model('Cat', schema);
var kitty = new Cat({ name: 'Zildjian' });
kitty.save(function (err) {
if (err) // ...
console.log('meow');
});
after the save call above the collection will be created
RBR
Updated on August 05, 2022Comments
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RBR almost 2 years
I'm new to node.js and mongodb.
I'm trying to create a schema for a User collection in a mongolab mongodb database from a node.js app with the code below. The code does not seem to be failing (at least, I get no error messages), but I don't see any indication that it is succeeding either. That is, when I go to mongolab and look at my database, I don't see that any schema was created - https://dzwonsemrish7.cloudfront.net/items/01263Y1c312s233V0R17/mongodb-schema.png?v=7fdc20e3.
Can someone explain what I might be doing wrong, or how I can verify that my code succeeded and a schema was, in fact, created for my collection?
// file: app.js var express = require('express'), http = require('http'), mongoose = require('mongoose'); var app = express(), port = 3000; // Connect to database in the cloud (mongolab) mongoose.connect('mongodb://username:[email protected]:41344/stockmarket'); // Create a schema for User collection mongoose.connection.on('open', function () { console.log(">>> Connected!"); var UserSchema = new mongoose.Schema({ username: {type: String, unique: true}, password: String }); var UserModel = mongoose.model('User', UserSchema); }); app.get('/', function(req, res){ res.writeHead(200, {'Content-Type': 'text/plain'}); res.end('Hello, World!\n'); }); http.createServer(app).listen(port, function(){ console.log("Express server listening on port " + port + " ..."); });
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RBR over 11 yearsHow do I do this? What should I add/change in the code above?
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Brian Cajes over 11 yearsYou have to review the mongoose API documentation. There are also examples around stack overflow eg. stackoverflow.com/q/10520501/579461
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RBR over 11 yearsI did read the mongoose doc, and it said: "A model is a class with which we construct documents." which implies that the model comes before the document, but you need a schema to create a model. So the order seems to be: schema -> model -> document. Sounds like you're saying the order is document -> schema -> model. I'm confused.
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Brian Cajes over 11 yearsThe order you mentioned is correct, but you have not created or inserted a document. Until you insert a document, the mongodb server will not create a collection in this case. Nothing is actually done on the server side when you define your mongoose schema or model. Updating answer with an example.
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RBR over 11 yearsAha! Thanks, Brian. Sorry for the confusion ... I'm reading this book (in the wee hours of the morning when I really should be sleeping instead), and [I thought] it said that after I create a Schema, I should see something in mongolab that shows the schema was created. This did not happen, so I thought my code was failing silently. But now I get it. Thanks again.