I've got a MongoDB database collection called Dealers structured a bit like this:
{
... dealer info goes here like address etc,
"user_logins": [
{
"Username": "something",
... other stuff
}
]
},{
... next dealer etc...
I'm using Mongoose to try and query on the user_logins.Username using this:
Mongoose model
const myTest = mongoose.Schema({
Username: {
type: "String",
required: true
}
}, { collection: "Dealers" })
module.exports = mongoose.model("Dealer", myTest);
The query
Dealer.find({'user_logins.Username' : 'something'}, (err, result) => {
if (err) {
console.log(err);
} else {
res.json(result);
}
});
All the Username's are distinct. But instead of returning the one matching document, it seems to be returning the whole Dealers collection.
I followed this example.
https://kb.objectrocket.com/mongo-db/use-mongoose-to-find-in-an-array-of-objects-1206
What am I doing wrong please?
Thanks.
EDIT: It seems fine if I try to find something on the root level. EG. Company name, address etc. But if I try to query an imbedded array of objects, that's when it pulls the whole collection. I don't get it.
Found the answer.
My model was wrong. It needed to reflect the actual structure of my data, which does kind of make sense.
This worked:
const myTest = mongoose.Schema({
user_logins: [{
Username: {
type: "String",
required: true
}
}]
}, { collection: "Dealers" })
module.exports = mongoose.model("Dealer", myTest);
Related
I can't push items into MongoDB array every time that i try to push a new element it creates an empty object and i cant figure out why,
I already used the
Collection.Array.push({element})&
Collection.save()
but i cant figure out a solution
This is My Schema
const Schema = mongoose.Schema;
var ParticipantSchema = new Schema({
nom:{Type:String},
prenom:{Type:String},
email:{Type:String}
})
var CompetitionSchema = new Schema({
nom:String,
date:Date,
place:String,
participant :[ParticipantSchema]
})
module.exports = mongoose.model("Competition",CompetitionSchema);
This is my funtion
exports.addParticipant=function(req,res){
var newParticipant={
"nom":req.body.nom,
"prenom":req.body.prenom,
"email":req.body.email
}
Competition.updateOne(
{ _id:req.body.id},
{ $push: { participant: newParticipant } },
(err,done)=>{
return res.json(done)
}
);
}
the result is always an empty object like below
{
"_id": "5ded0eeb85daa100dc5e57bf",
"nom": "Final",
"date": "2019-01-01T23:00:00.000Z",
"place": "Sousse",
"participant": [
{
"_id": "5ded0eeb85daa100dc5e57c0"
},
{
"_id": "5dee3c1b08474e27ac70672e"
}
],
"__v": 0
}
There is no problem in your code, the only problem is that in schema definition you have Type, but it must be type.
If you update your ParticipantSchema like this, it will work:
var ParticipantSchema = new Schema({
nom: { type: String },
prenom: { type: String },
email: { type: String }
});
You are using another Schema in the Array. This results in so-called subdocuments (https://mongoosejs.com/docs/subdocs.html). Mongoose does not populate subdocuments by default. So all you see is just the _id. You can use the populate method to see all subdocuments in detail. ( https://mongoosejs.com/docs/populate.html ) .
Example :
Competition.
find({}).
populate('participant').
exec(function (err, comps) {
//
});
You can either use populate on the Model or on the Document. For populating a document, take a look at https://mongoosejs.com/docs/api.html#document_Document-populate . There is also a auto-populate plugin available via npm but in most cases it's not necessary : https://www.npmjs.com/package/mongoose-autopopulate .
I have a simple embedded document:
{
"username":"user001",
"name":"John",
"tasks":[
{
"id":0,
"title":"Candy",
"description":"Lots of candy for you",
"category":"food",
"cost":2500,
"candyTypes":[
{"name":"gum", "type":"sweet", "price":"2"},
{"name":"chocolate", "type":"tasty", "price":"3"}
]
}
]
}
When I try to query the task data through the mongo shell, I get everything:
db.users.findOne({ 'username': 'user001', 'tasks.id':4 }, {'tasks.$':1})
/* returns */
"tasks":[
{
"id":0,
"title":"Candy",
"description":"Lots of candy for you",
"category":"food",
"cost":2500,
"candyTypes":[
{"name":"gum", "type":"sweet", "price":"2"},
{"name":"chocolate", "type":"tasty", "price":"3"}
]
}
]
But when I try to do the same in mongoose, the candyTypes array comes back empty:
Users.findOne({ 'username': username, 'tasks.id':taskId }, {'tasks.$':1}, function (err, data) {
console.log(data);
});
/* returns */
"tasks":[
{
"id":0,
"title":"Candy",
"description":"Lots of candy for you",
"category":"food",
"cost":2500,
"candyTypes":[]
}
]
I'm pretty new to MongoDB and Mongoose, but after searching and looking through documentation, I can't figure out what I'm missing.
UPDATE
I couple users requested it, so here is my mongoose schema:
var UserSchema = new mongoose.Schema({
username:String,
name:String,
tasks:[{
id: Number,
title: String,
description:String,
category: String,
cost: Number,
candyTypes:[{
title:String,
type:String,
value:String
}]
}]
});
With Mongoose, you have to populate candyTypes array:
Users.findOne({ 'username': username, 'tasks.id':taskId }, {'tasks.$':1})
.populate('candyTypes')
.exec(function (err, data) {
console.log(data);
});
See docs: http://mongoosejs.com/docs/populate.html
I think it's related to you declaring a field called type which also has a special meaning in Mongoose, namely to signify the type of a field.
If you rename that field to something else (candyType), it'll probably work better.
Alternatively, you can use the typeKey option to make Mongoose use a different property name to signify field type.
As an aside, your document contains a field price but your schema names it value.
I have two Schema defined as below:
var WorksnapsTimeEntry = BaseSchema.extend({
student: {
type: Schema.ObjectId,
ref: 'Student'
},
timeEntries: {
type: Object
}
});
var StudentSchema = BaseSchema.extend({
firstName: {
type: String,
trim: true,
default: ''
// validate: [validateLocalStrategyProperty, 'Please fill in your first name']
},
lastName: {
type: String,
trim: true,
default: ''
// validate: [validateLocalStrategyProperty, 'Please fill in your last name']
},
displayName: {
type: String,
trim: true
},
municipality: {
type: String
}
});
And I would like to loop thru each student and show it's time entries. So far I have this code which is obviously not right as I still dont know how do I join WorksnapTimeEntry schema table.
Student.find({ status: 'student' })
.populate('student')
.exec(function (err, students) {
if (err) {
return res.status(400).send({
message: errorHandler.getErrorMessage(err)
});
}
_.forEach(students, function (student) {
// show student with his time entries....
});
res.json(students);
});
Any one knows how do I achieve such thing?
As of version 3.2, you can use $lookup in aggregation pipeline to perform left outer join.
Student.aggregate([{
$lookup: {
from: "worksnapsTimeEntries", // collection name in db
localField: "_id",
foreignField: "student",
as: "worksnapsTimeEntries"
}
}]).exec(function(err, students) {
// students contain WorksnapsTimeEntries
});
You don't want .populate() here but instead you want two queries, where the first matches the Student objects to get the _id values, and the second will use $in to match the respective WorksnapsTimeEntry items for those "students".
Using async.waterfall just to avoid some indentation creep:
async.waterfall(
[
function(callback) {
Student.find({ "status": "student" },{ "_id": 1 },callback);
},
function(students,callback) {
WorksnapsTimeEntry.find({
"student": { "$in": students.map(function(el) {
return el._id
})
},callback);
}
],
function(err,results) {
if (err) {
// do something
} else {
// results are the matching entries
}
}
)
If you really must, then you can .populate("student") on the second query to get populated items from the other table.
The reverse case is to query on WorksnapsTimeEntry and return "everything", then filter out any null results from .populate() with a "match" query option:
WorksnapsTimeEntry.find().populate({
"path": "student",
"match": { "status": "student" }
}).exec(function(err,entries) {
// Now client side filter un-matched results
entries = entries.filter(function(entry) {
return entry.student != null;
});
// Anything not populated by the query condition is now removed
});
So that is not a desirable action, since the "database" is not filtering what is likely the bulk of results.
Unless you have a good reason not to do so, then you probably "should" be "embedding" the data instead. That way the properties like "status" are already available on the collection and additional queries are not required.
If you are using a NoSQL solution like MongoDB you should be embracing it's concepts, rather than sticking to relational design principles. If you are consistently modelling relationally, then you might as well use a relational database, since you won't be getting any benefit from the solution that has other ways to handle that.
It is late but will help many developers.
Verified with
"mongodb": "^3.6.2",
"mongoose": "^5.10.8",
Join two collections in mongoose
ProductModel.find({} , (err,records)=>{
if(records)
//reurn records
else
// throw new Error('xyz')
})
.populate('category','name') //select only category name joined collection
//.populate('category') // Select all detail
.skip(0).limit(20)
//.sort(createdAt : '-1')
.exec()
ProductModel Schema
const CustomSchema = new Schema({
category:{
type: Schema.ObjectId,
ref: 'Category'
},
...
}, {timestamps:true}, {collection: 'products'});
module.exports = model('Product',CustomSchema)
Category model schema
const CustomSchema = new Schema({
name: { type: String, required:true },
...
}, {collection: 'categories'});
module.exports = model('Category',CustomSchema)
Edit: this was actually working
As the Mongoose - Subdocs: "Adding subdocs" documentation says, we can add a subdoc using the push method (i.e. parent.children.push({ name: 'Liesl' });)
But I want to go further, and would like to use the $push operator to insert subdocuments.
I have two Schemas: the ThingSchema:
var ThingSchema = mongoose.Schema({
name: {
type: String,
required: true
},
description: {
type: String
}
});
and the BoxSchema, the main document that has an array of subdocuments (things) of ThingSchema:
var BoxSchema = new mongoose.Schema({
name: {
type: String,
required: true
},
description: {
type: String
},
things: {
type: [ThingSchema]
}
});
var BoxModel = mongoose.model('Box', BoxSchema);
I need every subdocument in things to have unique names - that is, that it would be impossible to insert a new document into this array that has a name value that already exists in the subdocs.
I'm trying to do something like:
var thingObj = ... // the 'thing' object to be inserted
BoxModel.update({
_id: some_box_id, // a valid 'box' ObjectId
"things.name": { "$ne": thingObj.name }
},
{
$push: { things: thingObj}
},
function(err) {
if (err) // handle err
...
});
but not getting any desired results.
What would be the correct way to add a ThingSchema subdocument into BoxSchema's thing array using the $push operator to do so in the query (must not add the subdoc if there's another subdoc named the same), instead of the Mongoose Docs way?
Edit: this is actually the issue
I made a mistake, the code above works as expected but now the problem I have is that when thingObj does not match the ThingSchema, an empty object is inserted into the things array:
// now thingObj is trash
var thingObj = { some: "trash", more: "trash" };
When executing the query given the above trash object, the following empty object is inserted into the subdocs array:
{ _id: ObjectId("an_obj_id") }
What I want this case, when the thingObj doesn't match the ThingSchema, is nothing to be added.
$addToSet adds something unique to the array (as in it checks for duplicates). But it only works for primitives.
What you should do is put things into their own collection and make a unique index on name. Then, make this change
things: {
type: [{type: ObjectId, ref: 'thingscollection'}]
}
this way you can do
BoxModel.update({
_id: some_box_id, // a valid 'box' ObjectId
"things": { "$ne": thingObj._id }
},
{
$addToSet: { things: thingObj._id}
},
function(err) {
if (err) // handle err
...
});
And when you fetch use .populate on things to get the full documents in there.
It's not exactly how you want it, but that's a design that might achieve what you're aiming for.
Schema of group and member are as below:
var group=new Schema({
group_id:Number,
group_name:String,
members:[member]
});
var member=new Schema({
member_id:number,
name:String,
});
Sample document after inserting some record in group collection
[{
_id:55ff7fca8d3f6607114dc57d
group_id:1001,
group_name:"tango mike",
members:[
{
_id:44ff7fca8d3f6607114dc21c
member_id:2001,
member_name:"Bob martin" ,
address:String,
sex:String
},
{
_id:22ff7fca8d3f6607114dc22d
member_id:2002,
member_name:"Marry",
address:String,
sex:String
},
{
_id:44ff7fca8d3f6607114dc23e
member_id:2003,
member_name:"Alice" ,
address:String,
sex:String
}
]
}]
My problem:
I am trying to update record of individual group member(element of subdocument members). While updating I have follwing data group: _id, group_id, members:_id and newdata. I am trying like this; but it is not working
var newData={
member_name:"Alice goda" ,
address:"xyz",
sex:"F"
}
groupModel.findOne({"_id":"55fdbaa7457aa1b9bd7f7cf7","group_id":1001},'members -_id',function(err,groupMembers){
if(err)
{
res.json({
"isError":true,
"error":{
"status":1042,
"message":err
}
});
}
else
{
var mem=groupMembers.id("44ff7fca8d3f6607114dc23e");
mem.member_name=newData.member_name;
mem.address=newData.address;
mem.sex=newData.sex;
mem.save(function(err,data){
if(!err)
//sucessfull updated
});
res.json(groupDetails);
}
});
As I understand from your question details, you would like to update one object from the members array, in accordance with the criteria that you specify.
Thus, in order to accurately run the update query for your use case, you could run the following update operation against your collection:
db.collection.update({ _id: "55ff7fca8d3f6607114dc57d",
group_id:1001,
members: {
$elemMatch: { _id: "44ff7fca8d3f6607114dc23e" }
}
},
{ $set: {
"members.$.member_name": "Alice goda",
"members.$.address": "xyz",
"members.$.sex": "F"
}});
Still, be aware that the $ positional operator only updates the first array item that matches your query.
Unfortunately, there is no possibility of updating all the array elements that match your criteria in a single operation. As you can see on MongoDB Jira, the aforementioned feature is one of the most requested functionality, but it has not yet been directly implemented in MongoDB.