Develop Reference

How can I add to this schema array with mongoose?

Here's the user schema and the part I want to update is ToDo under User.js (further down). I am attempting to add new data to an array within the db.
data.js
app.post("/data", loggedIn, async (req, res) => {
console.log(req.body.content);
let content = { content: req.body.content };
User.update({ _id: req.user._id }, { $set: req.body }, function (err, user) {
if (err) console.log(err);
if (!content) {
req.flash("error", "One or more fields are empty");
return res.redirect("/");
}
user.ToDo.push(content);
res.redirect("/main");
});
});
User.js
new mongoose.Schema({
email: String,
passwordHash: String,
ToDo: {
type: [],
},
date: {
type: Date,
default: Date.now,
},
})
Originally I was trying the .push() attribute, but I get the error:
user.ToDo.push(content);
^
TypeError: Cannot read property 'push' of undefined

First of all, your problem is the callback is not the user. When you use update the callback is something like this:
{ n: 1, nModified: 1, ok: 1 }
This is why the error is thrown.
Also I recommend specify the array value, something like this:
ToDo: {
type: [String],
}
The second recommendation is to do all you can into mongo query. If you can use a query to push the object, do this instead of store the object into memory, push using JS function and save again the object into DB.
Of course you can do that, but I think is worse.
Now, knowing this, if you only want to add a value into an array, try this query:
var update = await model.updateOne({
"email": "email"
},
{
"$push": {
"ToDo": "new value"
}
})
Check the example here
You are using $set to your object, so you are creating a new object with new values.
Check here how $set works.
If fields no exists, will be added, otherwise are updated. If you only want to add an element into an array from a specified field, you should $push into the field.
Following your code, maybe you wanted to do something similar to this:
model.findOne({ "email": "email" }, async function (err, user) {
//Here, user is the object user
user.ToDo.push("value")
user.save()
})
As I said before, that works, but is better do in a query.

JSON object architecture looks different when I pass it to the client side

Here is my Schema
var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var messageSchema = new Schema({
requestNumber: String,
requestedDateTime: String,
reasons: String,
state: String,
hospital: String,
phone: String,
status: {type: String, default: 'Pending'},
latestUpdate: Date,
createdAt: {type: Date, default: Date.now}
});
module.exports = mongoose.model('Requests', messageSchema);
Below I am returning the collection with three components in it
ipcMain.on('load-requests', function(event) {
hosSchemaModel.find(function(err, hosSchema) {
if (err) {
console.log('inside error') // return res.send(err);
} else {
event.sender.send('requests-results', hosSchema) // this line of code passes hosSchema to the client side
console.log(hosSchema[0].state) //prints the state attribute of the first component in the collection without any errors.
}
});
});
When I try to console.log(hosSchema) in the server, I get the following printed to the terminal:
and I could successfully access the properties such as status of the first component in the collection by referring to its index hosSchema[0].status.
Below I am trying to print hosSchema to the console (in the front-end)
ipcRenderer.on('requests-results', (event, hosSchema) => {
console.log(hosSchema)
})
I get the result different from what they were looking in the terminal. below is the picture
and hosSchema[0].status returns undefined.
My questions are:
1) why hosSchema[0].status doesn't work in the front-end?
2) what is the correct way to access the properties in the client-side?

All you have to do in the front end is to use hosSchema[0]._doc.status instead of hosSchema[0].status

array schema single value mongodb using node js

I am trying to fetch single value from my level collection using this level schema
After new Schema I use ( [] ) I don't know exactly the use of this. Why we use this. But my project requirement is to use this []
var LevelSchema = new Schema(
[
{
_id: { type: String },
age: { type: Number },
level_num: { type: Number },
min_score: { type: Number },
max_questions: { type: Number }
}
]);
So when I am trying to fetch the value using this node js
this.levelChange = function(req, res, next){
try{
var query = {level_num:1};
QuizLevels.find(query,function(err,data){
if(err){
return next(err);
}else if(data.min_score===10){
console.log(data.min_score);
}else{
console.log("Error");
}
});
}catch(err){
console.log(err);
}
};
I proper send all level information stored in my MongoDB to the browser. But when I am trying to fetch a single value field
min_score from the database and trying to send it in the browser or in the console it shows undefined. Means value cannot parse properly from MongoDB
to browser or console using this node js code.
so there are any further steps before to fetch this array schema.So that single value field parses properly to console
3). This is my JSON data
I am not sure that json data is exact according to level schema that i used to fetch.
{
"age":5,
"level_num":1,
"min_score":10,
"max_questions":30
}
{
"age":5,
"level_num":2,
"min_score":12,
"max_questions":33
}

Update/Put error save in Express and Mongoose

I am beginner in Express. I have the following code in my router/controller for update a model. In one hand I don't want to modify the date of "create_date" parameter, and on the second hand this code returns me a error.
updateFood = function(req, res){
Food.findById(req.params.id, function(err, food){
food.food_name = req.body.food_name;
food.description = req.body.description;
food.image = req.body.image;
food.create_date = Date.now();
food.category = req.body.category;
Food.save(function(err){
if (!err){
console.log("updated!");
} else {
console.log(err);
}
});
res.send(food);
});
};
Here is my schema:
var food = new Schema({
food_name: {type: String, unique: true},
description: String,
image: String,
create_date: {type: Date, default: Date.now()},
category: {
type: String,
cats: ['Meat', 'Fish', 'Vegetables']
}
});
module.exports = mongoose.model('Food', food);
When I try to update a food with Postman with PUT. The console returns me the following response:
Food.save(function(err){
^
TypeError: Object function model(doc, fields, skipId) {
if (!(this instanceof model))
return new model(doc, fields, skipId);
Model.call(this, doc, fields, skipId);
} has no method 'save'
What can I do? Anyone knows where is my mistake? Thanks.

I believe you meant food.save(..); instead of Food.save(..);, but if all you're doing is updating the model, you could use findByIdAndUpdate() instead.

How can I set composite primary key in mongodb through mongoose

I want to set primary key for two fields in a collection in mongodb through mongoose. I know to set composite primary key in mongodb as
db.yourcollection.ensureIndex( { fieldname1: 1, fieldname2: 1 }, { unique: true } )
but am using mongoose to handle mongodb I don't know how to set composite primary key from mongoose
update
I used mySchema.index({ ColorScaleID: 1, UserName: 1}, { unique: true });
see my code
var mongoose = require('mongoose')
var uristring ='mongodb://localhost/fresh';
var mongoOptions = { db: { safe: true } };
// Connect to Database
mongoose.connect(uristring, mongoOptions, function (err, res) {
if (err) {
console.log ('ERROR connecting to: remote' + uristring + '. ' + err);
} else {
console.log ('Successfully connected to: remote' + uristring);
}
});
var mySchema = mongoose.Schema({
ColorScaleID:String,
UserName:String,
Range1:Number,
})
mySchema.index({ ColorScaleID: 1, UserName: 1}, { unique: true });
var freshtime= mongoose.model("FreshTimeColorScaleInfo",mySchema)
var myVar = new freshtime({
ColorScaleID:'red',
UserName:'tab',
Range1:10
})
myVar.save()
mongoose.connection.close();
When I execute this code for first time I see a line {"_id":...,ColorScaleID:'red',UserName:'tab',Range1:10 } in mongodb's fresh database. When I execute the same code for second time I see two same lines.
{"_id":...,ColorScaleID:'red',UserName:'tab',Range1:10 }
{"_id":...,ColorScaleID:'red',UserName:'tab',Range1:10 }
If composite primary key worked then it shouldn't allow me to insert same data for second time. what would be the problem?

The way that you have defined your schema is correct and will work. What you are probably experiencing is that the database has already been created and that collection probably already exists even though it might be empty. Mongoose won't retro fit the index.
As an experiment, set your database to a DB that does not exist. e.g.:
var uristring ='mongodb://localhost/randomname';
and then try running those two lines against this database and see if you can still insert those two documents.
Then compare the contents of the "system.indexes" collection in each of those collections. You should see that the randomname db has the composite index correctly set.

As everybody mentioned, you got to use index method of a Schema to set composite unique key.
But this isn't enough, try restarting MongoDB after that.

May be you can try this in your mongoose schema model,
const AppSchema1 = new Schema({
_id :{appId:String, name:String},
name : String
});