So I have a few mongoose schema's defined.
var partSchema = mongoose.Schema({
name: String,
system: String,
team: Array,
quantity: Number,
});
var part = mongoose.model('part', partSchema);
var peopleSchema = mongoose.Schema({
name: String,
pass: String,
role: String,
parts: Array
});
var people = mongoose.model('people', peopleSchema);
And I want to send queries based on these schemas, and more, to the user. As such...
app.get('/', function(req, res){
people.find(function(err, persons){
if (err) return handleError(err);
console.log(persons);
parts.find(function(err, things){
res.render('in', { user: req.session.user, people:persons, parts:things });
});
});
});
To remain asynchronous, I would have to nest these calls, right? And I cant nest these calls, because "parts" is no longer defined. I'm wondering if I could do this, and how would I do it? Sorry if it's a noob question, but I've looked this up for days, and haven't seemed to find a solution. Thanks!
The variable name of your 'part' model is part, not parts. So it should be:
app.get('/', function(req, res){
people.find(function(err, persons){
if (err) return handleError(err);
console.log(persons);
part.find(function(err, things){ // <-- Changed on this line
res.render('in', {user: req.session.user, people:persons, parts:things});
});
});
});
Related
Im making a translation app, I want to have a new collection for each language.
When I go to /norwegian for instance I want to find from the collection of the same name.
How is this acheived?
at the moment I'm serving it like this.
// MONGOOSE/MODEL CONFIG
var norskSchema = new mongoose.Schema({
english: String,
phonetic: String,
category: String,
cat_id: Number,
lang: String
}, {collection: 'norwegian'});
var Norsk = mongoose.model("norwegian", norskSchema);
then calling
app.get('/norwegian', function(req, res){
Norsk.find(function(err, data) {
res.render('index', {data: data});
}).sort({ cat_id: 1});
});
Can I remove the collection object at the bottom of my schema and then call the same above adding a language as dot notation?
Trans.norwegian.find(function(err, data) {});
Trans.polish.find(function(err, data) {});
etc...
Thanks in advance.
As mentioned by #JohnnyHK you can do something like the following:
app.get('/norwegian', function(req, res){
mongoose.model('norwegian').find(function(err, data) {
res.render('index', {data: data});
}).sort({ cat_id: 1});
});
this should query with respect to a model without having to explicitly import the model .js object
I know there is allot's of answers about it but still I didn't quite get the idea.
I have CourseSchema:
const CourseSchema = new Schema({
course_name: String,
course_number: {type: String, unique : true },
enrolledStudents:[{
type: mongoose.Schema.Types.ObjectId,
ref: 'Student' }]
});
And a StudentSchema:
const StudentSchema = new Schema({
first_name: String,
last_name: String,
enrolledCourses:[{
type: mongoose.Schema.Types.ObjectId,
ref: 'CourseSchema'
}]
});
I want to reffer enrolledStudents at CourseSchema with a student, and enrolledCourses at StudentSchema with a course.
router.post('/addStudentToCourse', function (req, res) {
Course.findById(req.params.courseId, function(err, course){
course.enrolledStudents.push(Student.findById(req.params.studentId, function(error, student){
student.enrolledCourses.push(course).save();
})).save();
});
});
but when posting I get an error:
TypeError: Cannot read property 'enrolledStudents' of null
Ok so after readying Query-populate I did that:
router.post('/addStudentToCourse', function (req, res) {
Course.
findOne({ _id : req.body.courseId }).
populate({
path: 'enrolledStudents'
, match: { _id : req.body.studentId }
}).
exec(function (err, course) {
if (err) return handleError(err);
console.log('The course name is %s', course.course_name);
});
});
And when i'm hitting POST on postman I get on the console:
The course name is intro for cs
but it is loading for ever and later on console I get:
POST /courses/addStudentToCourse - - ms - -
You are missing the populate instruction. For example:
see more about it here
Course.
findOne({ courseId : req.params.courseId }).
populate('enrolledStudents').
exec(function (err, course) {
if (err) return handleError(err);
console.log('The course name is %s', course.name);
});
It is working by using the ref field that "knows" how to populate withput using the push syntax. it is like a foreign key population.
Just call the populate method on the query and an array of documents will be returned in place of the original _ids. you can learn more on the internals of the populate methods in the official docs
I am very new to Node.js and MongoDB and am trying to piece together my own blogging application. I have a problem trying to query through my 'Blog' model for ones with a specific username. When I try to run:
var userBlogs = function(username) {
ub = Blog.find({author: username}).toArray();
ub = ub.reverse();
};
I get an error:
TypeError: Object #<Query> has no method 'toArray'
I know globals are bad but I've just been trying to get it to work. The Mongo documentation claims that a cursor is returned which can have the toArray() method called on it. I have no idea why it won't work.
Here is my schema/model creation:
var blogSchema = mongoose.Schema({
title: {type:String, required: true},
author: String,
content: {type:String, required: true},
timestamp: String
});
var Blog = mongoose.model('Blog', blogSchema);
Here are the /login and /readblog requests
app.get('/readblog', ensureAuthenticated, function(req, res) {
res.render('readblog', {user: req.user, blogs: ub})
})
app.get('/login', function(req, res){
res.render('login', { user: req.user, message: req.session.messages });
});
app.post('/login',
passport.authenticate('local', { failureRedirect: '/login'}),
function(req, res) {
userBlogs(req.user.username);
res.redirect('/');
});
});
The end result is supposed to work with this Jade:
extends layout
block content
if blogs
for blog in blogs
h2= blog[title]
h4= blog[author]
p= blog[content]
h4= blog[timestamp]
a(href="/writeblog") Write a new blog
How can I get the query to output an array, or even work as an object?
The toArray function exists on the Cursor class from the Native MongoDB NodeJS driver (reference). The find method in MongooseJS returns a Query object (reference). There are a few ways you can do searches and return results.
As there are no synchronous calls in the NodeJS driver for MongoDB, you'll need to use an asynchronous pattern in all cases. Examples for MongoDB, which are often in JavaScript using the MongoDB Console imply that the native driver also supports similar functionality, which it does not.
var userBlogs = function(username, callback) {
Blog.find().where("author", username).
exec(function(err, blogs) {
// docs contains an array of MongooseJS Documents
// so you can return that...
// reverse does an in-place modification, so there's no reason
// to assign to something else ...
blogs.reverse();
callback(err, blogs);
});
};
Then, to call it:
userBlogs(req.user.username, function(err, blogs) {
if (err) {
/* panic! there was an error fetching the list of blogs */
return;
}
// do something with the blogs here ...
res.redirect('/');
});
You could also do sorting on a field (like a blog post date for example):
Blog.find().where("author", username).
sort("-postDate").exec(/* your callback function */);
The above code would sort in descending order based on a field called postDate (alternate syntax: sort({ postDate: -1}).
Try something along the lines of:
Blog.find({}).lean().exec(function (err, blogs) {
// ... do something awesome...
}
You should utilize the callback of find:
var userBlogs = function(username, next) {
Blog.find({author: username}, function(err, blogs) {
if (err) {
...
} else {
next(blogs)
}
})
}
Now you can get your blogs calling this function:
userBlogs(username, function(blogs) {
...
})
I'm still learning about node.js and mongodb. I'm trying to write simple app with nodejs and mongoose. My mongoose schema:
var todoSchema = new Schema({
task: String,
description: String,
date: Date,
status: String,
checklist: Boolean,
pic: String
});
I have collection named todos I'm trying to get the content of todos using this code:
apiRoutes.route('/todos/detail')
.get(function(req, res){
Todo.distinct( "pic" ).each(function(doc){
Todo.find({"pic": doc.pic}, function(err, todo){
if (err)
res.send(err);
var finalResult = [];
finalResult.push(todo);
res.send(finalResult);
});
});
});
But I got this error:
Object #<Query> has no method 'each'
Any idea to solve this? Really appreciate for the help.
From what I gather in your question, you don't necessarily need the loop since with the distinct pics array you are iterating over, you are using it to query the collection for each pic, which is
essentially equivalent to just querying the whole collection as sending the resulting array of documents returned from the query:
apiRoutes.route('/todos/detail').get(function(req, res){
Todo.find({"pic": { "$exists": true }}, function(err, todos){
if (err) res.send(err);
res.send(todos);
});
});
Unless you want to get a distinct list of pics, get the todo items with those pics you could try the following approach:
apiRoutes.route('/todos/detail').get(function(req, res){
Todo.find().distinct('pic', function(error, pics) {
// pics is an array of all pics
Todo.find({"pic": { "$in": pics } }, function(err, todos){
if (err) res.send(err);
res.send(todos);
});
});
});
For starting you should try with .forEach() instead of .each() first :)
Here you can see the forEach doc.
I am very new to Node.js and MongoDB and am trying to piece together my own blogging application. I have a problem trying to query through my 'Blog' model for ones with a specific username. When I try to run:
var userBlogs = function(username) {
ub = Blog.find({author: username}).toArray();
ub = ub.reverse();
};
I get an error:
TypeError: Object #<Query> has no method 'toArray'
I know globals are bad but I've just been trying to get it to work. The Mongo documentation claims that a cursor is returned which can have the toArray() method called on it. I have no idea why it won't work.
Here is my schema/model creation:
var blogSchema = mongoose.Schema({
title: {type:String, required: true},
author: String,
content: {type:String, required: true},
timestamp: String
});
var Blog = mongoose.model('Blog', blogSchema);
Here are the /login and /readblog requests
app.get('/readblog', ensureAuthenticated, function(req, res) {
res.render('readblog', {user: req.user, blogs: ub})
})
app.get('/login', function(req, res){
res.render('login', { user: req.user, message: req.session.messages });
});
app.post('/login',
passport.authenticate('local', { failureRedirect: '/login'}),
function(req, res) {
userBlogs(req.user.username);
res.redirect('/');
});
});
The end result is supposed to work with this Jade:
extends layout
block content
if blogs
for blog in blogs
h2= blog[title]
h4= blog[author]
p= blog[content]
h4= blog[timestamp]
a(href="/writeblog") Write a new blog
How can I get the query to output an array, or even work as an object?
The toArray function exists on the Cursor class from the Native MongoDB NodeJS driver (reference). The find method in MongooseJS returns a Query object (reference). There are a few ways you can do searches and return results.
As there are no synchronous calls in the NodeJS driver for MongoDB, you'll need to use an asynchronous pattern in all cases. Examples for MongoDB, which are often in JavaScript using the MongoDB Console imply that the native driver also supports similar functionality, which it does not.
var userBlogs = function(username, callback) {
Blog.find().where("author", username).
exec(function(err, blogs) {
// docs contains an array of MongooseJS Documents
// so you can return that...
// reverse does an in-place modification, so there's no reason
// to assign to something else ...
blogs.reverse();
callback(err, blogs);
});
};
Then, to call it:
userBlogs(req.user.username, function(err, blogs) {
if (err) {
/* panic! there was an error fetching the list of blogs */
return;
}
// do something with the blogs here ...
res.redirect('/');
});
You could also do sorting on a field (like a blog post date for example):
Blog.find().where("author", username).
sort("-postDate").exec(/* your callback function */);
The above code would sort in descending order based on a field called postDate (alternate syntax: sort({ postDate: -1}).
Try something along the lines of:
Blog.find({}).lean().exec(function (err, blogs) {
// ... do something awesome...
}
You should utilize the callback of find:
var userBlogs = function(username, next) {
Blog.find({author: username}, function(err, blogs) {
if (err) {
...
} else {
next(blogs)
}
})
}
Now you can get your blogs calling this function:
userBlogs(username, function(blogs) {
...
})