Get specific columns using “only()” function in Laravel Eloquent - php

I have two tables user and post.
in my posts method I want to return users posts with custom fileds.
none of below solutions dose not works
class UserController
{
public function posts(User $user)
{
return $user->only(['username', 'name', 'posts.body' // solution one
return $user->only(['username', 'name', 'posts'=>function($q){
$q->select(['body']
}])// solution two
Does anyone have a work around?

in post only get one column value in one row then used value method
Post::where('user_id')->value('body')
if you want to get multiple value(rows) from single column used pluck method
Post::where('user_id')->pluck('body') //this will get on the array
otherwise used select method
Post::select('body')->where('user_id')->get(); // this will get on collection
Post::select('body')->where('user_id')->get()->toArray(); // this will get on array

Related

Lumen/Laravel get attribute when using select and with

I've run into this issue a couple of times now and I can't seem to find a solution - I feel like I'm missing something obvious.
I am making a JSON API with Lumen, building up specific routes for specific use cases. To speed up load times, I only want to output the fields I will be using.
My model has a combination of fields, relations and attributes. I am struggling to specify the attribute when limiting output
For example:
A task has time_records. Each time_record has a value of time.
I want to output the task names, time record values plus an attribute of totalTime which I have set on the task like the below (this isn't the full code but hopefully it gets across the idea)
class Task extends Model {
protected $appends = [
'totalTime'
];
public function timeRecords() {
return $this->hasMany('TimeRecord');
}
public function getTotalTimeAttribute() {
$total = $this->timeRecords()->map(function($time_record){
return $time_record->value;
});
return array_sum($total);
}
}
If I then do the following:
Task::get();
And output that, I get all the tasks with the totalTime attribute. However, as mentioned I want to only output some attributes:
Task::select('id', 'name')
->with([
'timeRecord' => function($query){
$query->select('id');
}
])
No matter what I do, I can't seem to get the attribute output with that. The value is there in the array, but is null.
To resolve this, you have to select the fields that the attribute accesses.
Because I was only returning the ID of the time_record, the attribute was unable to calculate the total_time as the value field was not available.
(Was only while writing this question out did I discover the answer... 🙄)
You can get that using with() method without callback. Callback method provide you to filter results..
Task::select('id', 'name')
->with("timeRecords:id") // use comma for multiple columns
->get();

Calling Laravel relationship with aggregate

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;

Excluding Laravel appends values from model results

Laravel has the option to add an $appends array to each model making additional values automatically available as if they are database attributes by adding accessors for each.
This is normally pretty handy, except in this case I need to ONLY get the fields I put into select() because DataTables is expecting only what I send to it.
Example:
Item::select(['image', 'name', 'color']);
Will return appended fields after color in the attributes.
How do I force the exclusion of the appends values when returning results?
Or alternatively, how do I get DataTables to ignore certain attributes?
Not sure which is the least time costly route.
Currently using yajra/laravel-datatables package to send data to the jQuery DataTables AJAX request.
You can call each function in the collection object and then use setHidden method to exclude the unwanted fields like this
$item= Item::select(['image', 'name', 'color'])->get()->each(function($row){
$row->setHidden(['appendedField1', 'appendedField2']);
});
And for the yajra/laravel-datatables you can use something like
$item= Item::select(['image', 'name', 'color']);
return Datatables::of($item)->remove_column('appendedField1');
To solve this I added this method to my Item model:
public static function getAppends()
{
$vars = get_class_vars(__CLASS__);
return $vars['appends'];
}
Then used the following code in the controller:
$items = Item::select(['image', 'name', 'color']);
$DT = Datatables::of($items);
call_user_func_array([$DT, 'removeColumn'], Item::getAppends()); // Has to be called this way with yajra/laravel-datatables-oracle v3.* if passing an array.
return $DT->make(true);

Laravel nested relationship not working

I have a user model which stores basic user information such as username, password etc.
There are also 3 types of user, Student, Staff and Parent. Each type also has a seperate model. For example, there is a Student model which belongs to a User model.
I also have a relationships table, which stores relationships between students and parents. This relationship is stored in the User model.
If I do something like:
App\Student::first()->user->relations;
It happily returns a collection of related parents.
In my Students model, I have a method called hasParent() which accepts a given user ID, and checks to ensure the student has a parent with that id. In that method, I have the following:
public function hasParent($parent)
{
return $this->user->relations->where('id', $parent)->count() === 1;
}
However, this returns an error Cannot call 'where' on a non-object. If I debug further, $this->user->relations returns an empty array.
The problem is, like above, if I call the methods separately, I get the results I want.
So to clarify, if I run:
App\Student::first()->user->relations;
This returns a collection of users just fine.
In my Student model however, if I call:
$this->user
Then I get the correct student
If I call
$this->user->relations
I get an empty array. Which doesn't make sense! Can anyone shed any light on this, or what I might be doing wrong? If you need any further info, please let me know.
You need to call where on the relation like below.
public function hasParent($parent)
{
return $this->user->relations()->where('id', $parent)->count() === 1;
}
See the parenthesis after the relations. If you call the relation without the parenthesis Laravel returns you a collection. To get the builder you need to call the relation with the parenthesis.
I'd suggest - to avoid creating a huge query overhead (which you'll do by calling where and count on the Query builder, not the collection) - to do what you're doing already, except using Illuminate Collections filter-method:
public function hasParent($parent)
{
return $this->user->relations->filter(function($relation) use ($parent){return $entity->id === $parent;})->count() === 1;
}

Laravel belongsToMany to return specific columns only

So I have a many to many relationship between Users and Photos via the pivot table user_photo. I use belongsToMany('Photo') in my User model. However the trouble here is that I have a dozen columns in my Photo table most I don't need (especially during a json response). So an example would be:
//Grab user #987's photos:
User::with('photos')->find(987);
//json output:
{
id: 987,
name: "John Appleseed",
photos: {
id: 5435433,
date: ...,
name: 'feelsgoodman.jpg',
....// other columns that I don't need
}
}
Is it possible to modify this method such that Photos model will only return the accepted columns (say specified by an array ['name', 'date'])?
User.php
public function photos()
{
return $this->belongsToMany('Photo');
}
Note: I only want to select specific columns when doing a User->belongsToMany->Photo only. When doing something like Photo::all(), yes I would want all the columns as normal.
EDIT: I've tried Get specific columns using "with()" function in Laravel Eloquent but the columns are still being selected. Also https://github.com/laravel/laravel/issues/2306
You can use belongsToMany with select operation using laravel relationship.
public function photos()
{
return $this->belongsToMany('Photo')->select(array('name', 'date'));
}
Im assuming you have a column named user_id. Then you should be able to do the following:
public function photos()
{
return $this->belongsToMany('Photo')->select(['id', 'user_id', 'date', 'name']);
}
You have to select, the foreign key, else it will have no way of joining it.
Specifying the exact columns you want for the Photos relationship will likely end up biting you in the butt in the future, should your application's needs ever change. A better solution would be to only specify the data you want to return in that particular instance, i.e. the specific JSON response you're delivering.
Option 1: extend/overwrite the toArray() Eloquent function (which is called by toJson()) and change the information returned by it. This will affect every call to these methods, though, so it may end up giving you the same problems as doing select() in the original query.
Option 2: Create a specific method for your JSON response and call it instead of the general toJson(). That method could then do any data building / array modifications necessary to achieve the specific output you need.
Option 3: If you're working with an API or ajax calls in general that need a specific format, consider using a library such as League/Fractal, which is built for just such an occasion. (Phil is also working on a book on building APIs, and it doesn't suck.)

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