I am trying to make a twitter like feed in an application, I have a database called connections where inside there's user and follow and another database called feed containing owner which would equal to the follow column in connections.
What I could do if had every id of a follower statically is to use where('owner', '=' $follow) on each follower and return it.
I tried this approach but it wasn't ideal:
Get each follower inside connections;
foreach(follower) {
Get 10 of the latest posts orderBy "created_at";
Push into array;
}
shuffle array;
limit array to 15;
return array;
That also ended with the returned array not being ordered by created date.
How would I use eloquent to get the feed item only if the user follows the owner in the best/simplest way?
Are there any specific Laravel tools that can be used?
Also the database layout isn't fixed as it is, it can be altered if needed to better suite this.
You need to create a many-to-many relationship between the user and itself. See the laravel eloquent documentation http://laravel.com/docs/eloquent#relationships. I didn't test this code but it should be enough to get you started down the right track.
Create a pivot table called "user_following" with:
(int) id, (int) user_id, (int) following_id
Then do something like this:
<?php
// Model
class User extends Eloquent {
public function following()
{
return $this->belongsToMany('User', 'user_following', 'user_id', 'following_id');
}
public function tweets()
{
return $this->hasMany('Tweet')->orderBy('created_at', 'desc');
}
}
// controller
$tweetsOfWhoImFollowing = User::find($id)->following->tweets;
Related
If I have a Laravel 5.5 model called User that hasMany Posts and each Post hasMany Hits, is there an aggregate function I can call to get the total number of Hits for a User across all Posts, where the Hit was created in the last week?
It seems like there may be a clever way to do it besides doing something like
$hits = $user->posts()->hits()
and then looping over those hits to check created date.
In this case it seems like raw sql would be better, but I figured there may be an Eloquent way to handle a situation like this.
I think the right solution is just to use a HasManyThrough relationship to grab all the Hit rows, joined through the posts table.
So it'd look like this on the User model (roughly):
return $this->hasManyThrough(
Hit::class,
Post::class
// if you have non-standard key names you can specify them here-- see docs
);
Then when you have your User model you can just call $user->hits to get a collection of all the associated hits through all the user's Posts
You can add the code below to your Post model.
protected static function boot()
{
parent::boot();
static::addGlobalScope('hitCount', function ($builder) {
$builder->withCount('hits');
});
}
It automatically provides a field hits_count whenever you fetch a post.
$post = Post::first();
$hits = $post->hits_count; //Count hits that belongs to this post
You can read the documentation here to customize it to your need.
Set HasManyThrough relation in the User model:
public function hits()
{
return $this->hasManyThrough('App\Models\Hits','App\Models\Posts','user_id','post_id','id');
}
then you can do this:
$reults = $user->hits()->where('hits_table_name.created_at', '>=', Carbon::today()->subWeek())->count();
HasManyThrough Link
Use DB::enableQueryLog(); and DB::getQueryLog(); to see if executed SQL Query is correct;
What I'm trying to do is to show the posts that have been saved by the user in the profile. I will try to explain it as good as possible refering to my code. So:
public function userProfil($id)
I have the profile function which get the data from userprofile table. and inside I have the following code for saved data:
$authed = User::find($id);
$savedarticles = $authed->mysaves;
$allsavings = DB::select("Select * from article where id=$savedarticles->id");
But this code does not work like this anyway. I can do this instead:
$authed = User::find($id);
$savedarticles = $authed->mysaves;
But when I try to get articles from article table with the article_id of mysaves, it does not work such as this:
$allsaved= DB::table('article')->where('id', $savedarticles->article_id);
the error it gives is like:
Property [article_id] does not exist on this collection instance.
although savearticle table has article_id I can output it without the line above and in view I get them as:
#foreach($savedarticles as $savedarticle)
<p>{{$savedarticle}}</p>
#endforeach
it gives me everything that is in the savearticle table and I can get do savedarticle->article_id and get article_id but can't get it in controller.
I am using Laravel 5.4.
The error message Property [article_id] does not exist on this collection instance. means you are trying to get an attribute of a single instance but from a collection.
For example the collection could be like
[$article1, $article2, $article3]
therefore what you tried to do is something similar to
[$article1, $article2, $article3]->article_id
You are trying to get an attribute from a collection instead of a single instance.
As for your query, you can use where in sql statement to search for rows that match any item in an array
$allsaved= DB::table('article')->whereIn('id', $savedarticles->pluck('article_id')->all());
What I have understood is that A USER has many POSTS and a POST belong to an article.
If this is true then you have to do following.
1: In USER model define a relation to get all posts. like below.
public function posts() {
// Foreign key will be a key that is stored in posts table and represent the user MAY BE: user_id
$this->hasMany(Posts::class, 'foreign_key', 'local_key')
}
This will allow you to get all posts belong to a user.
2: In posts, model defines a user relation like below.
public function user() {
$this->belongsTo(User::class, 'foreign_key', 'local_key');
}
This will allow you to get a post User;
3: Now in your controller you will have something like this.
public function show($user_id) {
// find a user with posts as eager loading(to avoid query again)
$user = User::with(['posts'])->where('id', $user_id)->first();
// get all posts that belong to this user
$posts = $user->posts;
}
In controller show($user_id) method you will have a user data as well as user posts data. Now if you want to get a post relations then simply define as below. let say a post belongs to an article as well.
4: In posts, model defines a relation to get an article.
public function article() {
// This will allow you to get a post artcle
$this->belongsTo(Article::class, 'foreign_key', 'local_key');
}
Now you can get the article as well while finding a user. please see below. I am rewriting controller show action to give you a better understanding.
5: Get a user with user_id
public function show($user_id) {
// find a user with posts as eager loading(to avoid query again)
// eager loading for posts & post child, this will give you NOSQL at runtime and all data will come from one query.
$user = User::with(['posts', 'posts.article'])->where('id', $user_id)->first();
// get all posts that belong to this user
$posts = $user->posts;
foreach($posts as $post) {
$article = $post->article; // Child relation of post.
}
}
Hope you will understand the flow, you have to make sure models relation to work it perfectly. If you need further help please let me know.
I have gotten a model called User. in this model i have a function called UserActivity where i return this:
return $this->hasMany('App\UserActivity', 'userid');
After this i have a function that gets the activity name from the Activity table, but i do not know how to do this, i have currently gotten this:
public function Activity() {
return $this->hasManyThrough('App\UserActivity', 'App\Activity', 'userid', 'activityid');
}
And in my view i want to use this like this:
$activiteiten = \App\User::find(Auth::user()->id);
dd($activiteiten->UserActivity()->Activity());
But then i get an error saying this:
Call to undefined method Illuminate\Database\Query\Builder::Activity() (View: /var/www/vhosts/cpned.nl/intranet.cpned.nl/laravel/resources/views/dashboard.blade.php)
I can do it using inner joins but i am really wondering if i can do this with Laravel models. I do not know how currently, and because i don't know what the name is for the function in laravel i can't find it either, so I am sorry if this will be a duplicate.
My tables have the following keys and foreign keys:
Users: pk: id
user_activities: pk: userid, activityid
activities: pk: id
Thank you in advance!
You can try using eager loading.
So something like:
$activiteiten = \App\User::with('UserActivity.Activity')->find(Auth::user()->id);
dd($activiteiten->UserActivity->Activity);
Edit: So then you can do something like this:
foreach($activiteiten->UserActivity as $user_activity) {
foreach($user_activity->Activity as $activity) {
print_r($activity);
}
}
Shows how you can loop through the relationships.
The Activity function should be in the User model. So then you can call it this way:
$activiteiten = \App\User::find(Auth::user()->id);
dd($activiteiten->Activity); //gives you a collection of activities
However, you need belongsToMany function rather than hasManyThrough since the relationship between users and activities is many-to-many.
This mean you cut down going through the Intermediate model. You can check the doc on belongsToMany to understand what to do better.
A side note: Why are your functions name starting with capital letter?
Also using hasMany relations should affect the function name as well, so that 'activity' becomes 'activities' (just to keep the functionality and interpretation in sync).
Update:
//User model
public function activities() {
return $this->belongsToMany('App\Activity', 'user_activity', 'userid', 'activityid');
}
This uses the 'user_activity' table, to find the relationship between users and activities, so that you may now access by User::first()->activities for example.
I've found some query result really unexpected.
It's Laravel 5.2
We have following entity:
User with method:
public function roles() : BelongsToMany
{
return $this->belongsToMany(Role::class)->withPivot('timestamp');
}
Each User can have many roles, so we have also Role entity (but it doesn't matter much in my question) and pivot table user_role with timestamp field (and ids of course), because we hold information about time, when User achieved specific role.
I want to get all Users with theirs last assigned Role
When I create query (in User context in some repository):
$this->with(['roles' => function($query) {
$query->orderBy('timestamp', 'desc');
}])->all();
the result will contain Users with Roles entities inside itself ordered by timestamp - it's ok. But I want to retrieve only one last role inside each User entity not all ordered.
So...
$this->with(['roles' => function($query) {
$query->orderBy('timestamp', 'desc')->limit(1);
}])->all();
And then I retrieve Users but only User which achieved some Role for the very last time contains it! All the other Users have their roles field containing empty array.
Why ordering was performed on each Users relation separately, but when I added limit it behaved like a global limit for all.
It drives me crazy...
Thanks for advices.
EDIT
I've created lastRoles() method to get all Roles ordered desc. But all, retrieving one is impossible.
public function lastRoles() : BelongsToMany
{
return $this->BelongsToMany(Roles::class)->withPivot('timestamp')->latest('timestamp');
}
And for testing:
$users = (new User())->with('lastRoles')->get();
But now I must iterate over Users and invoke lastRoles() on each one:
foreach ($users as $user) {
var_dump($user->lastRoles()->get()->first()->name);
}
Then I retrieve names of latest Roles assigned to each User.
So... There is no way to do it in one query? This is the only way?
For this to work, you would need a helper function:
public function latestRole()
{
return $this->hasOne(Role::class)->withPivot('timestamp')->orderBy('timestamp', 'DESC');
}
And then:
$this->with('latestRole')->get();
Credits to this awesome article.
When you eager load a relationship with query constraint(s), the query will be run once to load all relationships, not each one individually. This is the expected behavior. Think about it, eager loading exists to turn many queries into one query in order to optimize performance. There is only one query executed, so your limit constraint will limit the entire result set, rather than on a per model basis.
To circumvent this, you could try creating another belongsToMany method that adds the desired limit constraint. The following code is untested:
public function lastRole() : BelongstoMany
{
return $this->belongsToMany(Role::class)
->withPivot('timestamp')
->orderBy('timestamp', 'desc')
->limit(1);
}
Assuming this works, you can then simply change the relationship method from roles to lastRole and remove your query constraint:
$this->with('lastRole')->all();
I am trying to figure out a relationship but I can't seem to solve the issue.
So what my script does first is checking if there is a valid session where status = 0.
Then I want to check if there is a valid trial where status = 0 ->first() associated with that session. And if so, I want to grab all the relevant data related by trial_id.
I understand what logic is required. However, I am wondering if there is a method to do this with as little commands as possible using Eloquent relationships.
Specifically, once i have the $session object. How can I filter the trials, in order to get the appropriate stimuli_tracker data?
The important components to the relationships for the table is as follows:
Sessions
id (has one to many relationship to trials(sessions_id)
user_id (foreign key)
status
Trials
id (one to many relationship with stimuli_tracker)
sessions_id (foreign key)
status
Stimuli_Tracker
trials_id (foreign key)
stimulus
stimulus_type
Sessions Model
class Sessions extends Model
{
protected $table = 'sessions';
public function stimuliTracker()
{
return $this->hasManyThrough('App\StimuliTracker', 'App\Trials', 'sessions_id','trials_id');
}
}
Trials Model:
class Trials extends Model
{
public function stimuli()
{
return $this->hasMany(App\StimuliTracker);
}
}
EDIT
I have tried in artisan tinker to
$object = \App\Session::where(arg);
then I tried to
$object->stimulus
but didn't work. I tried a few other fields but I only received null. Maybe I'm not getting how to grab the content properly
$object->stimulus is an undefined attribute based on what you've shown in your code.
To access the stimulus information for your session, you have to use the name of the relationship, which in this case is:
$object->stimuliTracker
The thing is that this will return an Eloquent Collection because it is a hasManyThrough relationship (which is a hasMany of a hasMany).
I'm assuming that the 'stimulus' attribute belongs to the StimuliTracker class. If this is the case, then you will need to loop through your StimuliTracker Collection to extract it:
foreach ( $object->stimuliTracker as $record )
{
$stimulus = $record->stimulus;
// do something with $stimulus
}
EDIT (Added):
If you are just looking for an array of the values in the 'stimulus' attribute, you can get that with the lists() method:
$stimulus_values = $object->stimuliTracker->lists('stimulus');