Hy there,
Before going to the hacky / cutom way i wanted to know if there is a built in query way to check for an empty / non empty many to many relationship as i was not successfull neither on google nor the doc.
If i take the example in the doc let's imagine i want to retrive a user only if he has a a Pet or Retrive a Pet without any Owner through a query.
// A user may have many pets
var User = Waterline.Collection.extend({
identity: 'user',
connection: 'local-postgresql',
attributes: {
firstName: 'string',
lastName: 'string',
// Add a reference to Pet
pets: {
collection: 'pet',
via: 'owners',
dominant: true
}
}
});
// A pet may have many owners
var Pet = Waterline.Collection.extend({
identity: 'pet',
connection: 'local-postgresql',
attributes: {
breed: 'string',
type: 'string',
name: 'string',
// Add a reference to User
owners: {
collection: 'user',
via: 'pets'
}
}
});
P.s. i know how to filter results after query execution that's not what i'm asking :)
There is nothing built in (aka User.hasPet() ) or something like that., so the simple answer is NO
If I know of these issues before hand I tend to write my DB in such a way that the queries are fast. IE: the User schema would have a hasPets column. Whenever a pet is added/removed a callbacks hits the user table to mark that field if it has an owner or not. So then I can query User.findAll({hasPet:true}).
Its a little much, but it depends on where you speed is needed.
This is a bit late, but I wanted to let you know it's pretty easy to do this with the Waterline ORM lifecycle functions. I've done it in a few of my projects. Basically, use the beforeCreate and beforeUpdate functions to set your flags. For your user, it might look like...
var User = Waterline.Collection.extend({
identity: 'user',
connection: 'local-postgresql',
beforeCreate: function(values, next) {
if (values.pets) {
values.has_pet = true;
} else {
values.has_pet = false;
}
next();
}
beforeUpdate: function(values, next) {
if (values.pets) {
values.has_pet = true;
} else {
values.has_pet = false;
}
next();
}
attributes: {
firstName: 'string',
lastName: 'string',
// Add a reference to Pet
pets: {
collection: 'pet',
via: 'owners',
dominant: true
},
has_pet: {
type: 'boolean'
}
}
});
Then you can query based on the has_pet attribute
Related
I am trying to create CRUD app in sails js, and i am able to post data to my DB what i noticed is when i insert data on success sails return whole object. But if we don't want certain fields in response then how can we restrict it. Please help thanks.
module.exports = {
attributes : {
username : {
type: 'string',
required: true
},
password : {
type: 'string',
required: true
},
email : {
type: 'string',
required: true,
unique: true
}
},
toJson: function() {
var obj = this.toObject();
delete obj.password;
return obj;
},
beforeCreate: function(attribute, callback) {
console.log(attribute.password);
require('bcrypt').hash(attribute.password, 10, function(err, encryptedPassword) {
sails.log(err);
attribute.password = encryptedPassword;
sails.log(encryptedPassword);
callback();
});
}
};
#arbuthnott is partly correct above -- you do need toJSON rather than toJson -- but more importantly, the function needs to go inside the attributes dictionary, since it is an instance method:
attributes : {
username : {
type: 'string',
required: true
},
password : {
type: 'string',
required: true
},
email : {
type: 'string',
required: true,
unique: true
},
toJSON: function() {
var obj = this.toObject();
delete obj.password;
return obj;
}
}
I think the responses through sails default REST api for models runs them through .toJSON before returning, so you are doing this the right way.
However, you may have a case issue, like you should define .toJSON with uppercase instead of .toJson. Try making that switch and see if it solves your problem.
UPDATE
Sounds like this is not solving your issue. The sails docs from here say:
The real power of toJSON relies on the fact every model instance sent out via res.json is first passed through toJSON. Instead of writing custom code for every controller action that uses a particular model (including the "out of the box" blueprints), you can manipulate outgoing records by simply overriding the default toJSON function in your model. You would use this to keep private data like email addresses and passwords from being sent back to every client.
That sounds pretty explicitly like what we are trying to do, so maybe this is a sails bug. Perhaps it applies to find, but not create. Is that password returned when simply finding an existing user?
If you must, a sure way around this would be to override the default create action in your UserController:
create: function(req, res) {
User.create(req.body).exec(function(err, user) {
if (err) {
return res.json(err);
}
// explicitly call your own toJSON() to be sure
return res.send(user.toJSON());
});
},
This isn't ideal, especially if you have many model properties you want to hide in many api calls. But it will get the job done.
password: { type: 'string', required: true, protected: true }
protected:true is now deprecated on sails v1.0
You can use instead of that customToJSON
customToJSON: function() {
// Return a shallow copy of this record with the password and ssn removed.
return _.omit(this, ['password', 'ssn'])
}
password: { type: 'string', required: true, protected: true }
You can do this also.
I need to select users with dogs (pets with type equal 'dog')
var User = Waterline.Collection.extend({
identity: 'user',
attributes: {
firstName: 'string',
lastName: 'string',
pets: {
collection: 'pet',
via: 'owner'
}
}
});
var Pet = Waterline.Collection.extend({
identity: 'pet',
attributes: {
type: 'string',
name: 'string',
owner: {
model: 'user'
}
}
});
I didn't find any examples, I tried like this
User.find().populate('pets', {type: 'dog'}).exec(err, users) ...
and this
User.find().where({'pets.type': 'dog'}).populate('pets').exec(err, users) ...
but that does not work
Would be greate if result users array will has no pets records
Did you try this?
User.find().populate('pets', {
where: {
type: 'dog'
}
}).exec(err, users)...
If you don't need to query users and just need the query for dogs. You could just as easily reverse the query.
Pet.find({type: 'dog'}).populate('users').exec(err, petsWithUsers)
What you are looking for hasn't been implemented in waterline (Sails ORM) yet, check issue #266 for more details.
User.find().populate('pets', {type: 'dog'}).exec(err, users) ...
This will return all users (User.find()) and only populate pets of type dog (populate('pets', {type: 'dog'})). So you'll have users without dogs in your results.
User.find().where({'pets.type': 'dog'}).populate('pets').exec(err, users) ...
Waterline does not support dot (.) notation. Sails-mongo does have some support for it due to MongoDB support.
Finally, if you are using one of the SQL adapters you may work around this by doing a raw sql query using .query() (docs).
I am trying to give a default association from a user to a pet, whenever a new User created.
Model:: User.js
var User = {
attributes: {
name: {type: 'string'},
// Add a One Way Relation to pet model
pets: {
collection: 'pet'
},
},
/*** This did not work ***/
beforeCreate: function (user, next) {
var defaultPet = {name: 'Default Pet 1'};
Pet.find(defaultPet).exec(function(err, pet) {
user.name = "BEFORECREATE",
user.pets = pet[0].id;
next();
});
},
}
module.exports = User;
However when a new record is created the user.pet is [ ], but user.name is changed to "BEFORECREATE".
How do I get user.pets = [{name: 'Default Pet 1'}] automatically for the new user created?
Or is there a better place for setting such defaults?
----- UPDATE: More info
I am using sails-disk currently.
Model: Pet.js
module.exports = {
attributes: {
name: {
type: 'string',
required: true
}
}
};
You can't add associations to a model in a lifecycle callback like beforeCreate. Currently, Waterline looks for and processes "nested models" like these before lifecycle callbacks run, so by the time beforeCreate is called it's too late. The simplest solution would be to create a User.createUser class method that wraps the logic you want:
createUser: function(data, cb) {
// If there are already pets specified, just use those
if (data.pets) {return User.create(data).exec(cb);}
// Otherwise look up the default pet
Pet.findOne({name:"Default Pet 1"}).exec(function(err,pet) {
// Return in case of error
if (err) {return cb(err);}
// Assuming the default pet exists, attach it
if (pet) {
console.log("SETTING DEFAULT PET", pet.id);
data.pets = [pet.id];
}
// Create the pet
return User.create(data).exec(cb);
});
}
A few notes:
In your example you were setting pets directly to an ID, but since it's a collection you must set it to an array.
If you're using the sails-disk adapter, you'll need to set schema: true in your model for this to work.
The new User model you get back will not be populated; you'll have to do a find with a populate('pets') with the new User ID to get the pet data attached.
I'm using MongoDB as a log keeper for my app to then sync mobile clients. I have this models set up in NodeJS:
var UserArticle = new Schema({
date: { type: Number, default: Math.round((new Date()).getTime() / 1000) }, //Timestamp!
user: [{type: Schema.ObjectId, ref: "User"}],
article: [{type: Schema.ObjectId, ref: "Article"}],
place: Number,
read: Number,
starred: Number,
source: String
});
mongoose.model("UserArticle",UserArticle);
var Log = new Schema({
user: [{type: Schema.ObjectId, ref: "User"}],
action: Number, // O => Insert, 1 => Update, 2 => Delete
uarticle: [{type: Schema.ObjectId, ref: "UserArticle"}],
timestamp: { type: Number, default: Math.round((new Date()).getTime() / 1000) }
});
mongoose.model("Log",Log);
When I want to retrive the log I use the follwing code:
var log = mongoose.model('Log');
log
.where("user", req.session.user)
.desc("timestamp")
.populate("uarticle")
.populate("uarticle.article")
.run(function (err, articles) {
if (err) {
console.log(err);
res.send(500);
return;
}
res.json(articles);
As you can see, I want mongoose to populate the "uarticle" field from the Log collection and, then, I want to populate the "article" field of the UserArticle ("uarticle").
But, using this code, Mongoose only populates "uarticle" using the UserArticle Model, but not the article field inside of uarticle.
Is it possible to accomplish it using Mongoose and populate() or I should do something else?
Thank you,
From what I've checked in the documentation and from what I hear from you, this cannot be achieved, but you can populate the "uarticle.article" documents yourself in the callback function.
However I want to point out another aspect which I consider more important. You have documents in collection A which reference collection B, and in collection B's documents you have another reference to documents in collection C.
You are either doing this wrong (I'm referring to the database structure), or you should be using a relational database such as MySQL here. MongoDB's power relies in the fact you can embed more information in documents, thus having to make lesser queries (having your data in a single collection). While referencing something is ok, having a reference and then another reference doesn't seem like you're taking the full advantage of MongoDB here.
Perhaps you would like to share your situation and the database structure so we could help you out more.
You can use the mongoose-deep-populate plugin to do this. Usage:
User.find({}, function (err, users) {
User.deepPopulate(users, 'uarticle.article', function (err, users) {
// now each user document includes uarticle and each uarticle includes article
})
})
Disclaimer: I'm the author of the plugin.
I faced the same problem,but after hours of efforts i find the solution.It can be without using any external plugin:)
applicantListToExport: function (query, callback) {
this
.find(query).select({'advtId': 0})
.populate({
path: 'influId',
model: 'influencer',
select: { '_id': 1,'user':1},
populate: {
path: 'userid',
model: 'User'
}
})
.populate('campaignId',{'campaignTitle':1})
.exec(callback);
}
Mongoose v5.5.5 seems to allow populate on a populated document.
You can even provide an array of multiple fields to populate on the populated document
var batch = await mstsBatchModel.findOne({_id: req.body.batchId})
.populate({path: 'loggedInUser', select: 'fname lname', model: 'userModel'})
.populate({path: 'invoiceIdArray', model: 'invoiceModel',
populate: [
{path: 'updatedBy', select: 'fname lname', model: 'userModel'},
{path: 'createdBy', select: 'fname lname', model: 'userModel'},
{path: 'aircraftId', select: 'tailNum', model: 'aircraftModel'}
]});
how about something like:
populate_deep = function(type, instance, complete, seen)
{
if (!seen)
seen = {};
if (seen[instance._id])
{
complete();
return;
}
seen[instance._id] = true;
// use meta util to get all "references" from the schema
var refs = meta.get_references(meta.schema(type));
if (!refs)
{
complete();
return;
}
var opts = [];
for (var i=0; i<refs.length; i++)
opts.push({path: refs[i].name, model: refs[i].ref});
mongoose.model(type).populate(instance, opts, function(err,o){
utils.forEach(refs, function (ref, next) {
if (ref.is_array)
utils.forEach(o[ref.name], function (v, lnext) {
populate_deep(ref.ref_type, v, lnext, seen);
}, next);
else
populate_deep(ref.ref_type, o[ref.name], next, seen);
}, complete);
});
}
meta utils is rough... want the src?
or you can simply pass an obj to the populate as:
const myFilterObj = {};
const populateObj = {
path: "parentFileds",
populate: {
path: "childFileds",
select: "childFiledsToSelect"
},
select: "parentFiledsToSelect"
};
Model.find(myFilterObj)
.populate(populateObj).exec((err, data) => console.log(data) );
I am using Mongoose to model Person and Transaction collections, where each Transaction will have references to two different Person instances:
var TransactionSchema = new Schema({
, amount : { type: Number, required: true }
, from : { type: ObjectId, required: true }
, to : { type: ObjectId, required: true }
, date : Date
});
var PersonSchema = new Schema({
name : { type: String, required: true }
, transactions : [ObjectId]
});
I'd like each Person to have a collection of all the Transactions that they are either the to or from value for. So far, this is the best way I've been able to figure out how to do it:
TransactionSchema.pre('save', function(next, done) {
var transaction = this;
Person.findById(this.to, function (err, person) {
person.transactions.push(transaction);
person.save();
});
Person.findById(this.from, function (err, person) {
person.transactions.push(transaction);
person.save();
});
next();
});
This seems excessive. Is there a better way to do it, or am I trying to use MongoDB too much like a relational database? Instead of having a collection of Transactions associated with each Person instance, should I just be querying the Translation collection directly?
Thank you.
You've got to think more on the queries you are going to execute on the database when you design the MongoDB schema.
Try to duplicate data for speed and reference it for integrity. What does that mean?
Well, for example when you make a query for a Transaction, I guess you don't need all the user details from the first time no? (do you need the user's email, location when displaying info on a Transaction?)
I think you just probably need the user id and the username, so you should do something like this:
var TransactionSchema = new Schema({
, amount : { type: Number, required: true }
, from : {
user_id: {
type: ObjectId
, required: true
}
, username: {
type: String
, required: true
}
}
, to : {
user_id: {
type: ObjectId
, required: true
}
, username: {
type: String
, required: true
}
}
, date : Date
});
So instead of doing 3 queries for the page displaying the Transaction details (one for the transaction and 2 additional queries for the usernames), you'll have just one.
This is just an example, you could apply the same logic for the User schema, depending on what you're trying to achieve.
Anyway I don't think your middleware is ok, since you are not checking for errors there (you are always calling next no matter what). This is how I would write the middleware (didn't test, but the idea is important):
TransactionSchema.pre('save', function(next, done) {
var transaction = this;
Person.where('_id').in([this.to, this.from]).run(function (err, people) {
if (people.length != 2) { next(new Error("To or from doesn't exist")); return; }
Step(
function save_to() {
people[0].transactions.push(transaction);
people[0].save(this);
},
function save_from(err) {
if (err) { next(err); return; }
people[1].transactions.push(transaction);
people[1].save(this);
},
function callback(err) {
next(err);
}
);
});
});
In the code above I'm using the Step library for flow control and I'm only using one query instead of two (when searching for "to" and "from").