I have 2 models: User and Team
There are multiple kinds of users (in this case Mentors and Moderators) which are differentiated using an attribute in the User model(). The associations between User and Team are as below:
User.hasMany(models.Team, {as: 'Mentors', through: models.TeamMentor, foreignKey: 'mentorId'});
User.hasMany(models.Team, {as: 'Moderators', through: models.TeamModerator, foreignKey: 'moderatorId'});
Team.hasMany(models.User, {through: models.TeamMentor, foreignKey: 'teamId'});
Team.hasMany(models.User, {through: models.TeamModerator, foreignKey: 'teamId'});
Now I am trying to get the details of the team along with separate objects for all the mentors and moderators that are assigned to the teams. I came to know about the getters and setters for many to many relationships from the documentation but I am not sure how to use the method since there are two different kinds of associations between two models here:
Team - Mentor (User)
Team - Moderator (User)
How to correctly query for a team's details in this case?
PS: TeamMentor and TeamModerator are empty models to help the many to many joins
I'm assuming you have N:M relationships between all those models? Like this:
User ---mentors many---> Teams
User --moderates many--> Teams
Team --is moderated by many--> Users
Team --is mentored by many---> Users
If so, you might want to use the as option not only in the User.hasMany(Team) that you already have, but also in the Team.hasMany(User):
Team.hasMany(models.User, {as: 'mentors', through: models.TeamMentor, foreignKey: 'teamId'});
Team.hasMany(models.User, {as: 'moderators', through: models.TeamModerator, foreignKey: 'teamId'});
I think you can then eager load some or all of them during a query like so:
Team.findAll({
where: {...},
include: [
{model: User, as: `moderators` },
{model: User, as: `mentors` }
// or just use this to include everything:
// include: [{all:true}]
]
}).then(function(teams) {
console.log(JSON.stringify(teams));
// oneTeam.moderators: [array of User]
// oneTeam.mentors: [array of User]
});
(side note: I think your User objects currently have a 'getMentors()' method, and a 'mentors' property, that is an array of Team. Same for the 'moderators' property. Perhaps renaming that to 'mentoredTeams' and 'moderatedTeams' would make it clearer?)
Related
rI am new to laravel 7 and I still have a few small difficulties.
I have two tables: users and services. These two tables have a relation to retrieve a user's service.
$users= User::with('poseur')->get();
It returns all users even those who do not meet the conditions of my relationship.
I use scope in service model:
public function scopePoseurs(){
return $query->whereRaw('slug','pos')
}
And i use belongsTo relation in user model :
public function poseur(){
return $this->belongsTo('App\Service')->poseurs();
}
Exemple: we hase 2 users:
first: Daniel have service slug = 'pos',
second: Patrick have service slug ='dev'
When i use $users=User::with('poseur')->get();, i see Daniel and Patrick.
While there should be only Daniel.
Can you help me understand ?
Thanks !
with() is for eager loading. That basically means, along the main model, Laravel will preload the relationship(s) you specify. This is especially helpful if you have a collection of models.
If you want to return all user, that has relation with poseur only, then use has() method :
$users= User::has('poseur')->get();
Ther is also a method called whereHas(), which allows you to specify additional filters for the related model to check :
$users = User::whereHas('poseur', function($q){
$q->where('created_at', '>=', '2020-01-01 00:00:00');
})->get();
I am trying to pull all the documents in the collection 'users', but it only pulls 'fred' and 'lisa', and ignores all the italicized documents:
For this data:
Trying to get all documents:
Will yield:
info: length 2
info: fred => { gender: 'male', contacts: [ '' ] }
lisa => { contacts: [ '' ] }
According to the Firebase documentation (Firebase: Add and Manage Data):
Warning: Even though non-existent ancestor documents appear in the console, they do not appear in queries and snapshots. You must create the document to include it in query results.
Note: The non-existent ancestor users seem to be auto-created when the user hits the sign-up button that triggers a firebase.auth() function (fred and lisa were created manually).
How would I print the contacts of each user if some of the users do not show up in my queries? Would I need to periodically run a script that manually re-adds all the users or is there a more elegant solution?
As you have mentioned, these "documents" are displayed with an italic font in the Firebase console: this is because these documents are only present (in the console) as "container" of one or more sub-collection but they are not "genuine" documents.
As matter of fact, if you create a document directly under a col1 collection with the full path doc1/subCol1/subDoc1, no intermediate documents will be created (i.e. no doc1 document).
The Firebase console shows this kind of "container" (or "placeholder") in italics in order to "materialize" the hierarchy and allow you to navigate to the subDoc1 document but doc1 document doesn't exist in the Firestore database.
Let's take an example: Imagine a doc1 document under the col1 collection
col1/doc1/
and another one subDoc1 under the subCol1 (sub-)collection
col1/doc1/subCol1/subDoc1
Actually, from a technical perspective, they are not at all relating to each other. They just share a part of their path but nothing else. One side effect of this is that if you delete a document, its sub-collection(s) still exist.
So, if you want to be able to query for these parent documents, you will have to create them yourself, as jackz314 mentioned in the comments.
If you're trying to list all your registered users from Firebase auth, you can use the Firebase SDK function:
function listAllUsers(nextPageToken) {
admin.auth().listUsers(1000, nextPageToken)
.then(function(listUsersResult){
listUsersResult.users.forEach(function(userRecord) {
console.log('user', userRecord.toJSON());
})
if (listUsersResult.pageToken) {
// list next batch of users
}
})
.catch(function(err) {
console.log('Error listing users: ', error)
});
}
listAllUsers();
via http://firebase.google.com/docs/auth/admin/manage-users#list_all_users
I want to have the users in the database structured in a way that makes it easier for a human to read and manage. Using the users email address as the property name instead of the User ID:
Users:
"Users" : {
"emailaddress#domain.com":{
"id": "DK66qu2dfUHt4ASfy36sdfYHS9fh",
"name": "A Display Name",
"groups": {
"moderators": true,
"users": true
}
},
{...}
}
So that if I have a list of users in a group, they can be read as a list of emails and not a list of user IDs.
Groups Such as:
"Groups": {
"moderators":{
"name": "moderator",
"members": {
"emailaddress#domain.com": true,
"emailaddress2#domain.com": true
}
}
}
Groups Instead of:
"Groups": {
"moderators":{
"name": "moderator",
"members": {
"DK66qu2dfUHt4ASfy36sdfYHS9fh": true,
"K2fkHYQDFOge3Hw7SjRaGP3N2sdo": true
}
}
}
However, using rules to verify a property of the user (such as their group), would require me to maintain two list of users, one like the list above, and another essentially a table of key-value pairs of ID's and email addresses so I can get the users email address from their uid.
Pseudo-code rule: Users[UsersKeyVal[auth.uid]].groups.moderator == true
With firebase, what would be considered the most acceptable practice? What are the pros and cons of both?
Please do not store user data under their email address! This will be BIG TROUBLE later.
Your users node should follow the 'standard' Firebase design pattern
users
uid_0
name:
gender:
etc
uid_1
name:
gender:
etc
The bottom line is that in general, it's best to disassociate the dynamic data stored in the node from the key of the node.
Why?
Suppose you build a complex structure with all kinds of links and references to frank#mycoolcompany.com and then #mycoolcompany.com gets acquired by #mynotsocoolcompany.com. Well, you will then have to go in and rebuild every reference to franks's email in the entire database. ugh.
Then what if there are 100 or 1000 users #mycoolcompany.com! Ouch.
If you disassociate the data, like my per above suggested structure, you just change the email address within the node and everything else... just works!
PLEASE, read this answer on stack overflow - written by a Firebaser and addresses your question
Firebase data structure and url
In my opinion there is no problem with your data structure.
According to the Doc
This is a necessary redundancy for two-way relationships. It allows you to quickly and efficiently fetch your members memberships
Also using the generated UId from firebase or your custom Id (here your e-mail) doesn't change the way firebase works. You just have to make sure your e-mail are unique.
I have videos that can be liked by users and commented by users so I need 2 many to many associations.
User model
User.belongsToMany(models.Video,{ through: 'user_like_video' });
User.belongsToMany(models.Video, { through: 'user_comment_video' });
Video model
Video.belongsToMany(models.User, {through: 'user_like_video'});
Video.belongsToMany(models.User, {through: 'user_comment_video'});
My resulting schema in DB is :
The many to many relationship between video a tags work well I can use the method getTags() to retrieve all the tags from a video but how are created methods when you have 2 (many to many relationship) ?
When I use user.getVideos(), I only get the last relation registered which is here user_comment_video.
I finally find a way :
Video.belongsToMany(models.User, {through: 'user_like_video', as: 'Like'});
Video.belongsToMany(models.User, {through: 'user_comment_video',as: 'Comment'});
this exposes methods getLike() and getComment()
I am trying to create a backbone client side application. I am receiving a list of json objects from the server on startup that will be a list of the possible tables exposed from the server, with their structure. E.g. Customers, Orders, Invoices, Employees
I want to create the models, collections and views dynamically based on the data I receive from the server.
Only when I receive the json on load will I know what the models should be and what the relationships between the models should be.
E.g. Customers structure might be Id, CustomerName, Address, Contact Numbers.
Order Structure might be Id, CustomerId, OrderDate, Amount
etc
By building Models, collections, views, controllers dynamically, I could in theory on startup point at another server who might give me a totally different set of tables e.g. : Movies, Actors etc.. with their structures.
Also, if additional fields are added I don't have to change the client side code again. E.g. Customer table might include a new field called ContactPerson
Please assist me as all the examples I saw on backbone is all based on statically defining the models on the client side up front. So create a model and collections and views for Customers, Orders, Invoices, Employees etc. etc.
Best wishes,
Andy
As already mentioned in the comments, Backbone models are dynamic by nature. So this is perfectly valid for example:
// A example dataset, this could be returned as JSON from the server
var jsonDataA = [
{
name: "Foo",
title: "Bar"
},
{
name: "a",
title: "b"
}
],
// A different example dataset
jsonDataB = [
{
make: "X",
model: "Y"
},
{
make: "Z",
model: "ZZ"
}
],
MyModel = Backbone.Model.extend({
/* Empty Model definition */
}),
MyCollection = Backbone.Collection.extend({
model: MyModel
}),
collection = new MyCollection();
collection.reset(jsonDataA);
console.log(collection.models);
collection.reset(jsonDataB);
console.log(collections.models);
Here I have reused the same Collection and Model definition to store completely different datasets.
One part is the raw data, the other part is its relations. You need to transport the metadata also, which contains the types and their relations. Model attributes will be populated automatically.
From your metadata a simple object can be constructed, where the keys describe one entity, for example:
var entites = {};
entities["Customer"] = Backbone.Model.extend({
/* Model definition based on metadata */
});
var parametersFromServer = {name: "John Doe"};
var customer = new entities["Customer"](parametersFromServer);
For building relations I would recommend using BackboneRelational plugin.