I am creating an api using MongoDB, I am using Mongoose to create Data Persistence. However I am getting an error that Mongoose is not defined, I have used require function to call the node module but it is still giving me the same error.
Below is the connection file
var mongoose = require('mongoose')
var database = 'api'
const server = 'mongodb://localhost:27017/'+database
console.log(server)
mongoose.connect(server)
const db = mongoose.connection
console.log(db)
var Schema = mongoose.Schema
var ObjectId = Schema.ObjectId
const WeatherSchema = new Schema({
id: {type: String, required: true},
name: { type: String, required: true },
items: {type: String, required: true}
})
var WeatherDB = mongoose.model('DBlist', WeatherSchema)
You should wait for the database to connect, as it doesn't happen immediately. Something like this:
var mongoose = require('mongoose');
mongoose.connect(sever);
var db = mongoose.connection;
db.on('disconnect', connect); // auto reconnecting
db.on('error', function(err) {
debug('connection error:', err);
});
db.once('open', function (callback) {
// we're in the game, start using your Schema
const WeatherSchema = new Schema({...
});
p.s.
I've added little extra sugar just to let you know these events exist and are quite helpful to understand what's going on.
Related
I'm currently using the following code. I'm basically using the example from the mongoose documentation but I'm trying to get the name field to be unique
here I am intentionally creating two unique "kittens" and trying to save both of them
const mongoose = require("mongoose");
mongoose.connect("mongodb://localhost/test", {
useNewUrlParser: true,
useUnifiedTopology: true,
useCreateIndex: true
});
const db = mongoose.connection;
db.on("error", console.error.bind(console, "connection error:"));
db.once("open", function () {
console.log("Connected to database");
});
const kittySchema = new mongoose.Schema({
name: { type: String, unique: true },
});
kittySchema.methods.speak = function () {
const greeting = this.name
? "Meow name is " + this.name
: "I don't have a name";
console.log(greeting);
};
const Kitten = mongoose.model("Kitten", kittySchema);
const fluffy = new Kitten({ name: "fluffy" });
fluffy.save();
const fluffy2 = new Kitten({ name: "fluffy" });
fluffy2.save();
Using the unique property doesn't seem to work because I keep getting duplicate entries in the database. I've also tried using the removedups key in the schema which I believe has been deprecated.
This property unique is not for data to be saved uniquely. It's for unique indexing that will be applied on field.
You can chech documentation here.
https://joshtronic.com/2018/06/07/unique-indexes-with-mongodb-and-mongoose/
I have my schema as this
var Schema = mongoose.Schema;
var schema = new Schema({
uid : {type: String, required: true},
title: {type: String, required: true},
description: {type: String, required: true}
})
module.exports = mongoose.model('Task', schema)
In another file, I include this file, and try to seed the db:
var Task = require('../models/task');
var uuid4 = require('uuid4')
var mongoose = require('mongoose')
mongoose.Promise = global.Promise;
mongoose.connect('mongodb://localhost:27017/app', {useNewUrlParser: true});
var task = new Task({
uid: uuid4(),
title: 'task3 name',
description: 'task3 desc'
})
task.save(function (err) {
if (err) console.log(err)
})
}
No matter what I do, it won't save the data I want.
Now, when I dive into the db, app database, tasks collection, there are no inserts over there
version: "mongoose": "^5.5.2",
According to this documentation
If you create a custom connection, use that connection's model() function instead.
var connection = mongoose.createConnection('mongodb://localhost:27017/test');
var Tank = connection.model('Tank', yourSchema);
So you need to declare your model from your connection so that it knows which connection to associate the .save() action.
I would recommend creating a dedicated db.js file that handles creating the connection which can then be imported into each of your schema files in order to create the model from the supplied connection.
var mongo = require('mongoose');
var connection = mongo.createConnection('mongodb://127.0.0.1/test');
connection.on("error", function(errorObject){
console.log(errorObject);
console.log('ONERROR');
});
var Schema = mongo.Schema;
var BookSchema = new Schema({ title : {type : String, index : {unique : true}}});
var BookModel = mongo.model('abook', BookSchema);
var b = new BookModel({title : 'aaaaaa'});
b.save( function(e){
if(e){
console.log('error')
}else{
console.log('no error')
}});
Neither the 'error', or 'no error' are printed to the terminal. What's more the connection.on 'error' doesn't seem to fire either. I have confirmed that MongoDb is running.
this is a case where you are adding the model to the global mongoose object but opening a separate connection mongo.createConnection() that the models are not part of. Since the model has no connection it cannot save to the db.
this is solved either by connecting to mongo on the global mongoose connection:
var connection = mongo.createConnection('mongodb://127.0.0.1/test');
// becomes
var connection = mongo.connect('mongodb://127.0.0.1/test');
or by adding your models to your separate connection:
var BookModel = mongo.model('abook', BookSchema);
// becomes
var BookModel = connection.model('abook', BookSchema);
I really like Aaron's answer, and thanks to him I am now on my way to fixing the issue... although I'm not there yet! Here is my particular issue:
I want to have my schema and models defined in separate files, so I can reuse them from project to project. So as an example I have a file named W8DBItem.js as follows:
var mongoose = require('mongoose');
var itemSchema = new mongoose.Schema({ name: {type: String, required: true}});
module.exports = mongoose.model('W8DBItem', itemSchema);
In my program file I do this this:
var mongoose = require('mongoose');
var W8DBItem = require('../w8/W8DBItem.js');
var dbURL ='mongodb://localhost:27017/default';
var mongoOptions = { useNewUrlParser: true, bufferCommands: false }
mongoose.connect(dbURL, mongoOptions);
var db = mongoose.connection;
// DEAL WITH CONNECTION ERROR
db.on('error', console.error.bind(console, 'connection error:'));
// PREP DATA
var aWeight = { name: "My Test Name" };
var newWeightItem = W8DBItem(aWeight);
// CONNECTION ESTABLISHED
db.once('open', function() {
console.log("Here 1")
// TRY TO SAVE
newWeightItem.save(function (err, newWeightItem) {
if (err) {
console.log("Here 2");
console.log(err);
}
else {
console.log("Here 3");
console.log(newWeightItem);
}
});
});
When I run this program I get "Here 1" but never "Here 2" or "Here 3" in the console.
From Aaron's post I get that the W8DBItem object has no associated (and open) connections, but I am not sure how to go about fixing things. I could connect to the DB in the W8DBItem.js file, but I really don't like hard-coding the server info with the objects - I want these objects to be used in different files, and perhaps with different servers.
Ideas and suggestions are much appreciated!
[EDIT: SOLUTION FOUND!!!]
Instead of exporting my mongoose.model from my object file, I am only exporting the schema:
var mongoose = require('mongoose');
var itemSchema = new mongoose.Schema({name: {type: String, required: true}});
module.exports = itemSchema;
In my program files I then do this:
var itemSchema = require('../w8/W8DBItemSchema.js');
...
var W8DBItem = db.model('W8DBItem', itemSchema);
var newWeightItem = W8DBItem(aWeight);
...
Works like a charm. I hope this helps someone!
The posted answer does not solve the problem. Unfortunately, I cannot just upgrade my database, so that is not a solution either for me. But here I found a solution to this problem: https://github.com/Automattic/mongoose/issues/4064
Just use .$__save instead of .save as shown:
var b = new BookModel({title : 'aaaaaa'});
b.$__save({}, function(e){
if(e){
console.log('error')
// callback will show if e exists
}else{
console.log('no error')
// callback will show 'no error'
}});
i'm making a simple blog app using nodejs + express, i can add first post without a problem but when i try to add second post i got his error { MongoError: E11000 duplicate key error collection: restful_blog_app_v2.blogs index: username_1 dup key: { : null }
this is my schema
var mongoose = require("mongoose");
var passportLocalMongoose = require("passport-local-mongoose");
var BlogSchema = new mongoose.Schema({
title: String,
image: String,
body: String,
created: {
type: Date,
default: Date.now
},
author: {
id: {
type: mongoose.Schema.Types.ObjectId,
ref: "User"
},
username: String
}
});
BlogSchema.plugin(passportLocalMongoose);
module.exports = mongoose.model("Blog", BlogSchema);
this is the user schema
var mongoose = require("mongoose");
var passportLocalMongoose = require("passport-local-mongoose");
var UserSchema = new mongoose.Schema({
username: String,
password: String,
});
UserSchema.plugin(passportLocalMongoose);
module.exports = mongoose.model("User", UserSchema);
this is the create new post route
app.post("/blogs", isLoggedIn, function (req, res) {
req.body.blog.body = req.sanitize(req.body.blog.body);
var title = req.body.blog.title;
var image = req.body.blog.image
var body = req.body.blog.body;
var created = req.body.blog.created;
var author = {
id: req.user._id,
username: req.user.username
}
var newPost = {
title: title,
image: image,
body: body,
created: created,
author: author
}
Blog.create(newPost, function (err, newBlog) {
if (err) {
console.log(err);
res.render("new");
} else {
console.log(newBlog);
res.redirect("/blogs");
}
});
});
I've tried to dropped the entire database using db.dropDatabase() from the mongo console but the problem still persist, not sure what to do now
This is caused by passport-local-mongoose, which, according to its fine manual, makes username a unique field by default.
You have added this plugin to BlogSchema, which seems like you initially had the user data in that schema but moved it to a separate schema (UserSchema) and forgot to remove it from the former.
Start by not using it for BlogSchema, and you also need to drop the unique index on username on the blogs collection.
Can you try deleting your Schema and again send the value? I was getting the same issues. I solved with the above idea.
I have the following code to insert record in Mongo by using Mongoose.
var mongoose = require('mongoose');
var config = require ('config');
var db = mongoose.createConnection(config.database.address, config.database.dbName);
var strCollectionName = 'category';
var CategorySchema = new mongoose.Schema({
categoryName : {type: String, required: true , unique: true },
categoryTag : {type: String},
categoryDescription : {type: String},
createDate : {type: Date, default: Date.now}
});
var createCategory = function (objCategory)
{
var Category = db.model(strCollectionName, CategorySchema );
var objSchema = new Category(objCategory);
objSchema.save(function (err)
{
if (err)
console.log ("Error");
else
console.log ("Success !!");
});
}
I managed to make it work. But if i try to issue db.close () command inside save it throws error otherwise it is good. My questions is I should not have to close the connection at all ? Will Mongoose automatically takes care it ? - Im worried if the connection pool goes beyond the limit then the entire DB might crash.
To do this properly:
Define your models and tell Mongoose about them at the same time. You can do this before you create the connection.
You were previously telling Mongoose about your schema right when you wanted to use it - you only need to do this once, when you create the schema itself.
You can then open a connection for Mongoose which will work across your whole application (i.e. to use it subsequently, you just have to require('mongoose')):
var mongoose = require('mongoose');
var config = require ('config');
var CategorySchema = new mongoose.Schema({
categoryName : {type: String, required: true , unique: true },
categoryTag : {type: String},
categoryDescription : {type: String},
createDate : {type: Date, default: Date.now}
});
mongoose.model('Category', CategorySchema);
mongoose.connect(config.database.address, config.database.dbName);
If you want to manually create and manage connections you can, using .createConnection as in your example above, but unless you know what you're doing it's better to just use Mongoose's default connection.
To create a category:
// if you're in a different file to where you created your CategorySchema, var these:
var mongoose = require('mongoose'),
Category = mongoose.model("Category");
var createCategory = function (objCategory) {
var newCategory = new Category(objCategory);
newCategory.save(function (err) {
if (err)
console.log ("Error");
else
console.log ("Success !!");
});
}