NodeJS & Mongoose: Add element to existing empty array - arrays

I am building a NodeJS application for creating reports based on data from a MSQL database. All application relevant data is stored in a MongoDB using Mongoose. My mongoose model contains an empty array which is then filled by the user via a Rest-API.
I get an error when adding a new element to the array. I already tried it with model.array.push(object); model.save() and findByIdAndUpdate(...). Find my code including the two different attempts below:
Mongoose schema
var sqlSchema = mongoose.Schema({ // Schema to store information about SQL-procedures
'name': String,
'inputs': [
{
'name': String,
'type': String,
'value': String,
'adjustable': Boolean
}
]
});
REST API
My application accepts new elements for the 'inputs'-array via POST:
var mongoose = require('mongoose'),
SqlProcedure = mongoose.model('SqlProcedure');
// ...
router.post('/sql/:id/inputs', function(req, res) {
SqlProcedure.findById(req.params.id, function(err, sql) {
if(err) {
res.send(msg.error('error retrieving sql-procedure', err));
} else {
if(sql.inputs.length > 0) { // catch empty array
for(var key in sql.inputs) {
if(sql.inputs[key].name == req.body.name) {
return res.send(msg.error('input already in inputs', err));
}
}
}
var data = req.body;
var input = {
name: data.name,
type: data.type,
value: data.value,
adjustable: data.adjustable
};
// attempt one or two
}
});
});
attempt one:
sql.inputs.push(input); // EXCEPTION 1
sql.save(function(err) {
// fancy errorhandling
return res.send(msg.ok(sql));
});
attempt two:
SqlProcedure.findByIdAndUpdate(req.params.id,
{$push: {inputs: input}}, // EXCEPTION 2
{safe: true, upsert: true},
function(err, sql) {
// fancy errorhandling
res.send(msg.ok('input added to sql-procedure' + req.params.id));
}
);
Exceptions
Attempt one:
throw new CastError('string', value, this.path);
^
Error
at MongooseError.CastError (\node_modules\mongoose\lib\error\cast.js:18:16)
at SchemaString.cast (\node_modules\mongoose\lib\schema\string.js:434:9)
at Array.MongooseArray.mixin._cast (\node_modules\mongoose\lib\types\array.js:124:32)
at Array.MongooseArray.mixin._mapCast (\node_modules\mongoose\lib\types\array.js:295:17)
at Object.map (native)
at Array.MongooseArray.mixin.push (\node_modules\mongoose\lib\types\array.js:308:25)
at Query.<anonymous> (\app\api\sql_procedure.js:69:28)
at \node_modules\mongoose\node_modules\kareem\index.js:177:19
at \node_modules\mongoose\node_modules\kareem\index.js:109:16
at doNTCallback0 (node.js:417:9)
at process._tickCallback (node.js:346:13)
Attempt two:
"stack": "Error
at MongooseError.CastError (\\node_modules\\mongoose\\lib\\error\\cast.js:18:16)
at SchemaArray.cast (\\node_modules\\mongoose\\lib\\schema\\array.js:156:15)
at SchemaArray.cast (\\node_modules\\mongoose\\lib\\schema\\array.js:167:17)
at Query._castUpdateVal (\\node_modules\\mongoose\\lib\\query.js:2384:22)
at Query._walkUpdatePath (\\node_modules\\mongoose\\lib\\query.js:2298:27)
at Query._castUpdate (\\node_modules\\mongoose\\lib\\query.js:2227:23)
at castDoc (\\node_modules\\mongoose\\lib\\query.js:2430:18)
at Query._findAndModify (\\node_modules\\mongoose\\lib\\query.js:1752:17)
at Query._findOneAndUpdate (\\node_modules\\mongoose\\lib\\query.js:1620:8)
at \\ITZReport\\node_modules\\mongoose\\node_modules\\kareem\\index.js:156:8
at \\node_modules\\mongoose\\node_modules\\kareem\\index.js:18:7
at doNTCallback0 (node.js:417:9)\n at process._tickCallback (node.js:346:13)",
"message": "Cast to undefined failed for value \"[object Object]\" at path \"inputs\"",
"name": "CastError",
"value": [
{
"adjustable": "true",
"value": "Harry Potter",
"type": "String",
"name": "salesman"
}
],
"path": "inputs"
data to be inserted
{ name: 'salesman',
type: 'String',
value: 'Harry Potter',
adjustable: 'true' }
I am new to NodeJS and mongoose and tried to solve this on my own for many hours. It would be great if anyone out there could help me!
Thanks in advance,
dj2bee
Update
I think I should clarify the process of the user interacting with the REST-API:
The user creates a new record by passing over the value for the
name. At this point the name is set and the inputs-array
is empty.
In the next step, the user adds new records to the
inputs-array one by one. The name stays as it is and only
new inputs are added to the array.
The user should be able to edit or remove entries from the
inputs-array.
Changing the data-type of adjustable to String did not made any changes. I also tried hard coding attributes and not passing them via HTTP-POST - still the same exception.

After hours of searching the web and testing the weirdest things in my code I found the solution:
You can't name a field 'type' in the mongoose-schema. That's it.
The correct code looks like this:
Mongoose schema
var sqlSchema = mongoose.Schema({
'name': String,
'inputs': {
'name': String,
'datatype': String, // you can't name this field 'type'
'value': String,
'adjustable': Boolean
}
});
REST API
router.post('/sql/:id/inputs', function(req, res) {
SqlProcedure.findById(req.params.id, function(err, sql) {
if(err) {
res.send(msg.error('error retrieving sql-procedure', err));
} else {
if(!sql) {
return res.send(msg.error('no sql-procedure found with id '
+ req.params.id, null));
}
// check for duplicates
var data = req.body;
var input = {
'name': data.name,
'datatype': data.type,
'value': data.value,
'adjustable': data.adjustable
};
SqlProcedure.findByIdAndUpdate(req.params.id,
{$push: {inputs: input}},
{safe: true, upsert: true},
function(err, sql) {
// fancy error handling
}
);
}
});
});

You should make your data to be inserted as
{ name: 'salesman',
inputs: [{name: 'salesman',
type: 'String',
value: 'Harry Potter',
adjustable: true}]}
i.e. true without quotes and inputs as an array
or else in schema make adjustable as String and remove input as array in model definition
var sqlSchema = mongoose.Schema({ // Schema to store information about SQL-procedures
'name': String,
'type': String,
'value': String,
'adjustable': String
});

Related

mongoose + nodejs push array to database

I'm new to NodeJS + Mongoose and having trouble pushing an array to my database via mongoose.
I have the following schema:
const StudentSchema = mongoose.Schema({
name: {
type: String
},
quizzes: [{
quiz: String,
answers: []
}]
});
What I'm trying to do is have an array of quiz objects in which the quiz number is shown and the array of answers for that particular quiz.
When I create a new user, the student object looks like this in mongoose:
{
"_id" : ObjectId(id here),
"name" : "John",
"quizzes" : [ ],
"__v" : 0
}
The function I'm using to update the quiz array:
module.exports.addQuiz = function(student_id, answers, callback){
Student.findByIdAndUpdate(
student_id,
{$push: {"quizzes": {answers: answers}}},
{safe: true, upsert: true},
function(err, model) {
console.log(err);
}
);
}
And this is my route which calls the function whenever the endpoint is hit with a student_id, which will then be used to find the student and push to the array
router.post('/quiz/:student_id', (req, res, next) => {
var student_id = req.params.id;
var answers = req.body.answers;
Student.addQuiz(student_id, answers, (err, answers) => {
//error handling
})
});
I'm trying to test this by sending a post request to /quiz/:student_id with an id of a student in my database with the following JSON sent in the body:
[{
"quiz": "Quiz 1",
"answers": ["Answer 1", "Answer 2"]
}]
Although when I try this it ends up getting hung somewhere and the request never completes - I also get a "null" in the console.
Can anyone help me out? Thank you.

Mongo schema, array of string with unique values

I'm creating the schema for a mongo document and I can do everything except prevent duplicates in a non-object array.
I'm aware of the addToSet, but I'm referring to Mongo Schema.
I don't want to check on Update using $addToSet, rather I want this to be part of my schema validation.
Example below.
let sampleSchema = {
name: { type: 'String', unique: true },
tags: [{ type: 'String', unique: true }]
}
The above snippet prevents name from having duplicate values. It allows tags to be stored as a string array.
But.. I cannot limit the array to be unique strings.
{ name: 'fail scenario', tags: ['bad', 'bad', 'array']}
I'm able to insert this record which should be a fail scenario.
const express = require('express');
const router = express.Router();
const mongoose = require('mongoose');
const _ = require('underscore');
let sampleSchema = new mongoose.Schema({
name: {
type: 'String',
unique: true
},
tags: [{
type: 'String'
}]
})
sampleSchema.pre('save', function (next) {
this.tags = _.uniq(this.tags);
next();
});
const Sample = mongoose.model('sample', sampleSchema, 'samples');
router.post('/sample', function (req, res, next) {
const sample = new Sample(req.body);
sample.save()
.then((sample) => {
return res.send(sample);
})
.catch(err => {
return res.status(500).send(err.message);
})
});
I've come to the conclusion that this is impossible to do via Mongoose Schema.
JSON schema is done like so.
let schema = {
name: { type: 'string' }
tags: {
type: 'array',
items: { type: 'string', uniqueItems: true }
}
}
I'll validate with JSON schema before creating Mongo Document.
This method builds on Med's answer, handles references, and done completely in scheme validation.
let sampleSchema = new mongoose.Schema({
strings: [{type: 'String'}],
references: [{type: mongoose.Schema.Types.ObjectId, ref: 'Reference'],
});
sampleSchema.pre('save', function (next) {
let sample = this;
sample.strings = _.uniq(sample.strings, function(i) {return (i._id) ? i._id.toString() : i;});
sample.references = _.uniq(sample.references, function(i) {return (i._id) ? i._id.toString() : i;});
return next();
});
I'm a little late, but maybe this will help someone in the future.
const mongoose = require('mongoose');
const userSchema = new mongoose.Schema({
name: {
type: String,
},
reference: {
type: [mongoose.Schema.Types.ObjectId],
ref: 'SomeOtherSchema',
// Add a custom validator.
validate: {
// The actual validator function goes here.
// "arr" will be the value that's being validated (so an array of
// mongoose new ObjectId statements, in this case).
validator: arr => {
// Convert all of the items in the array "arr", to their string
// representations.
// Then, use those strings to create a Set (which only stores unique
// values).
const s = new Set(arr.map(String));
// Compare the Set and Array's sizes, to see if there were any
// duplicates. If they're not equal, there was a duplicate, and
// validation will fail.
return s.size === arr.length;
},
// Provide a more meaningful error message.
message: p => `The values provided for '${ p.path }', ` +
`[${ p.value }], contains duplicates.`,
}
},
});
The above commented code should be pretty self explanatory.
With the newer version(s) of MongoDB, you can use $addToSet to append to an array if and only if the new value is unique compared to the items of the array.
Here's the reference: https://www.mongodb.com/docs/manual/reference/operator/update/addToSet/
Here's an example:
const SampleSchema = new mongoose.Schema({
tags: [String]
});
const Sample = mongoose.model('Sample', SampleSchema);
// append to array only if value is unique
Sample.findByIdAndUpdate({_id: 1, {$addToSet: {tags: "New Tag"}}});
This will effectively update the tags if the "New Tag" is not already present in the tags array. Otherwise, no operation is done.

NodeJS/MongoDB - Match Value in Array with a Value from a Logged In User

I want Users to be able to Report a File/Video only once. By pushing the users ID to a Array, then check if the user has already reported the file.
So far I am able to find the current user, then the VideoID, increment by 1 and then push it to the reportedBy array. But I am pretty lost, when it comes to checking if the current user has already reported the file. Any tips/help will be much appreciated! :-)
MY ROUTE
router.get('/report/:videoLink', function(req, res, next){
async.waterfall([
function(callback){
User.findOne({_id: req.user._id}, function(err, foundUser){
if(err) return next(err)
callback(err, foundUser)
})
},
function(foundUser, callback){
Video.findOne({videoLink: req.params.videoLink}, function(err, reportVideo){
reportVideo.reports++;
reportVideo.reportedBy.push(foundUser);
if (reportVideo.reports > 4) {
reportVideo.remove();
}
reportVideo.save(function(err){
if(err) return next();
});
res.redirect('/');
});
}
]);
});
MY SCHEMA
var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var random = require('mongoose-simple-random');
var fragSchema = new Schema({
title: String,
videoLink: {type: String, unique: true, required: true},
category: String,
upVotes: {type: Number, default: 0},
downVotes: {type: Number, default: 0},
voted: {type: Boolean, default: false},
reports: {type: Number, default: 0},
reportedBy: [{ type: Schema.Types.ObjectId, ref: 'User'}],
ownByUser: {type: Schema.Types.ObjectId, ref: 'User'},
date: { type: Date, default: Date.now }
});
fragSchema.plugin(random);
module.exports = mongoose.model('Frag', fragSchema);
This should find the video only if it was reported by that user before:
Video.findOne({
videoLink: req.params.videoLink,
reportedBy: foundUser._id,
}, ...
and this should find the video only if it was not reported before:
Video.findOne({
videoLink: req.params.videoLink,
reportedBy: {$nin: [foundUser._id]},
}, ...
There are many ways to achieve that but you get the idea.
If you want to find the video anyway an then test if it was already reported by that user then something like this inside of your Video.findOne callback:
if (reportVideo.reportedBy.indexOf(foundUser._id) < 0) {
// not reported by that user yet
} else {
// already reported by that user
}
If you're using lodash then you can use:
if (_.includes(reportVideo.reportedBy, foundUser._id)) {
// already reported by that user
} else {
// not reported by that user yet
}
Make sure that you have the IDs as strings, maybe you will need to use .toString() or something like that before the comparisons.

How to get data from array in mongoose?

I am new to mongoose node.js and mongoDB, I have a db Schema like
Project:{
projectName:"String",
projectManager:"String",
task:[{
taskName:"String",
timetakeninhrs:"String"
}]
};
So what I want is to get only the details of task with particular task name.
I am writing sql script so that you can know what I want :
Select taskname,timetakeninhrs from project where taskName ='DB create';
The $elemMatch projection operator would come in handy for this:
Project
.where('task.taskName', 'DB create') // or where('task.taskName').equals('DB create').
.select({_id: 0, task: {$elemMatch: {'taskName': 'DB create'}})
.exec(function(err, docs){
var tasks = docs.map(function(doc){ return doc.task[0]; });
console.log(tasks[0].taskName); // 'DB create'
console.log(tasks[0].timetakeninhrs); // '3'
});
In the above, the where() method acts as a static helper method of the Mongoose model that builds up a query using chaining syntax, rather than specifying a JSON object. So
// instead of writing:
Project.find({ 'task.taskName': 'DB create' }, callback);
// you can instead write:
Project.where('task.taskName', 'DB create');
// or
Project.where('task.taskName').equals('DB create');
and then chain the select() method to project the 'task' array field using $elemMatch. In the exec() method (which executes the query asynchronously), you need to pass in a callback which follows the pattern callback(error, results). What results is depends on the operation: For findOne() it is a potentially-null single document, find() a list of documents, count() the number of documents, update() the number of documents affected, etc. In this case this returns an array of documents in the format:
[
/* 0 */
{
"task" : [
{
"taskName" : "DB create",
"timetakeninhrs" : "3"
}
]
},
/* 1 */
{
"task" : [
{
"taskName" : "DB create",
"timetakeninhrs" : "9"
}
]
}
/* etc */
]
In your callback you can do a bit of data manipulation to get an object that only has those properties you specified, hence the use of the native JavaScript map() function to create a new array of objects with those fields
i create this example that can help you:
var async=require('async');
var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var uri = 'mongodb://localhost/myDb';
mongoose.connect(uri);
// define a schema
var ProjectSchema = new Schema({
projectName: "String",
projectManager: "String",
task: [{
taskName: "String",
timetakeninhrs: "String"
}]
});
// compile our model
var Project = mongoose.model('Project', ProjectSchema);
// create a documents
var Project01 = new Project({
projectName: "Project01",
projectManager: "Manager01",
task: [{
taskName: "tsk01_Project01",
timetakeninhrs: "1111-1111"
}, {
taskName: "tsk02_Project01",
timetakeninhrs: "1111-2222"
}, {
taskName: "tsk03_Project01",
timetakeninhrs: "1111-3333"
}, {
taskName: "tsk04_Project01",
timetakeninhrs: "1111-4444"
}]
});
var Project02 = new Project({
projectName: "Project02",
projectManager: "Manager02",
task: [{
taskName: "tsk01_Project02",
timetakeninhrs: "2222-1111"
}, {
taskName: "tsk02_Project02",
timetakeninhrs: "2222-2222"
}, {
taskName: "tsk03_Project02",
timetakeninhrs: "2222-3333"
}, {
taskName: "tsk04_Project02",
timetakeninhrs: "2222-4444"
}]
});
//delete existing documents and create them again
Project.remove({}, function() {
Project01.save(function() {
Project02.save(function() {
//for example we find taskName: "tsk03_Project02"
Project.find({'task': {$elemMatch: {taskName: "tsk03_Project02"}}},'task.taskname task.timetakeninhrs',function(err, docs) {
if (!err) {
console.log(docs);
}
});
});
});
});

How to query mongoose by property that is and array item

I have a mongoose model that looks like this:
var mongoose = require('mongoose')
, Schema = mongoose.Schema;
var PictureSchema = new Schema({
listId: { type: Array, required: true },
thumb: { type: String, required: true },
large: { type: String, required: true }
});
var Picture = module.exports = mongoose.model('Picture', PictureSchema);
I am trying to update instances of this model in my router by looking up a Picture via the "listId" property. Like this:
app.put('/pictures/append', function(req, res) {
var targetListId = req.body.targetListId
, currentListId = req.body.currentListId;
Picture
.find({ listId: currentListId }, function (err, picture) {
console.log('found pic', picture);
picture.listId.push(targetListId);
picture.save(function(err, pic) {
console.log('pic SAVED', pic);
});
});
});
"currentListId" is a string, and listId is an array of currentListId's. Maybe this isn't the correct way to query a a property that is an array?
I am getting an error:
TypeError: Cannot call method 'push' of undefined
On the line:
picture.listId.push(targetListId);
But when I look up the picture models in mongo, they DO have listId arrays and some DO contain the item "currentListId" that I am using for my query.
I tried using $elemMatch and $in but I don't know if I was using them correctly.
Any idea if I am just writing my query wrong?
Specifying an Array typed field in your schema is equivalent to Mixed which tells Mongoose that field could contain anything. Instead, change your schema to something like this:
var PictureSchema = new Schema({
listId: [String],
thumb: { type: String, required: true },
large: { type: String, required: true }
});

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