A More Efficient Way to Query Relationships - laravel

I'm building a query on a table (product).
product has a foreign key, wrapper_id,
each wrapper, in turn, has a foreign key wrapper_classification_id.
This part of the query needs to modify the search based on an array of wrapper_classification_id's that may have been passed as input parameters.
This is what I'm doing:
// $query is already being built from above this line....
// wrapper_classification_id in input is an array
if (Input::get('wrapper_classification_id'))
{
$wrappers = Wrapper::whereIn('wrapper_classification_id', Input::get('wrapper_classification_id'))->get();
$wrapperArray = [];
foreach($wrappers as $wrapper) {
$wrapperArray[] = $wrapper->id;
}
$query->whereIn('wrapper_id', $wrapperArray );
}
Is there a more efficient way of approaching this scenario where you're querying against a value in a relationship?
Thanks in advance,
Rich

$query->whereIn(
'wrapper_id',
DB::raw(
Wrapper::whereIn(
'wrapper_classification_id',
Input::get('wrapper_classification_id')
)->toSql()
)
);
Or, try joins.
$query->join('wrapper AS w', 'w.wrapper_classification_id', 'IN', Input::get('wrapper_classification_id'))
->whereIn('product.wrapper_id', 'w.id');
Not sure if that exact code would work though.

Assuming the product model has a wrapper relationship:
if (Input::has('wrapper_classification_id'))
{
$query->whereHas('wrapper', function($q){
$q->whereIn('wrapper_classification_id', Input::get('wrapper_classification_id'));
});
}

Related

Query Builder filter for multi level deep relationship in Laravel

I have a selection of plots which each belong to a development by a hasManyThrough relationship through housetypes. I want to filter these by development on their overview page. Plots has a housetype_id column and housetypes has a development_id column.
public function plots()
{
return $this->hasManyThrough(Plot::class, Housetype::class);
}
When I use my filter it returns the developments ID number as $development, I then need this to only show plots which are linked to that development.
I have looked into using whereHas or Join methods but have been unable to figure this out. Current filter scope is below. Thanks
public function scopeFilterDevelopment($query)
{
$development = request()->input('filter_development');
if ($development == "") {
return;
}
if(!empty($development)){
$query->where('development_id', $development);
}
}
If I can understand it right you wish to assert a condition on other Model, HasMany will load all the objects to the related model once the query is completed. Eloquent then binds the related model objects to each.
Try joins from Laravel instead. I feel this is what you exactly want: https://laravel.com/docs/5.8/queries#joins
I would use whereHas to filter the relationship:
YourModel::whereHas('plots', function($query) {
$query->filterDevelopment();
})->get();
I would also edit the query scope not to rely on the request global function, but instead pass the development of value as a parameter.
you have make a leftjon and then use when, you dont have to use
if(!empty($development)){
$query->where('development_id', $development);
}
this any more, you can use
->when($development=="" ? false : true, function($query) use ($development){
return $query->where('development_id', $development);
})
this is a full example
$queryBuilder = DB::table('facturas')->
leftJoin('clientes','clientes.id','=','facturas.clientes_id')->
select('facturas.estados_id as estado','facturas.numero as
numero',DB::raw('concat(clientes.nombre," ",clientes.apellido) as cliente'))->
when($estados===null ? false: true,function($query) use ($estados){
return $query->whereIn('facturas.estados_id', $estados);
})
It was a whereHas that solved this in the end! (another developer at work walked me through this)
Relationship -
public function housetype()
{
return $this->belongsTo(Housetype::class);
}
Function -
public function scopeFilterDevelopment($query)
{
if (request()->input('filter_development') == "") {
return;
}else{
$query->whereHas('housetype', function($housetype){
$housetype->where('development_id', request()->input('filter_development'));
});
}
}
This then returns any plot where its housetype has a matching development_id for the filter_development from the request.
Thanks for everyone's input

Does "where" works with mutattors in eloquent?

I have a mutattor in an eloquent model that generates a "status" atribute.
public function getStatusAttribute(){
if(){
return "enabled";
}
else
{
return "disabled";
}
}
Can I use?
$query = Anuncio::query();
$query->where('status', "enabled" );
return $query->get();
I seems that I cannot. I getting "status" column not defined. How can I get around this problem?
No doesn't works it works on model level
you can use after query from database in collection result
No, when you are doing a query you are asking the database, therefor there needs to be a column status.
There is a way, retrieve x elements from the database and use the Laravel Collection method where(). This is not optimal if you have many elements in teh database, it will retrieve all of them.
Anuncio::all()->where('status', 'enabled')->all();

Laravel / Eloquent: Is it possible to select all child model data without setting a parent?

I have various parent/child relationships, drilling down a few levels. What I want to know is if its possible to do something like this:
$student = Student::find(1);
$student->bursaries()->enrolments()->courses()->where('course','LIKE','%B%');
(With the end goal of selecting the course which is like '%B%'), or if I would have to instead use the DB Query builder with joins?
Models / Relationships
Student:
public function bursaries() {
return $this->hasMany('App\StudentBursary');
}
StudentBursary:
public function enrolments() {
return $this->hasMany('App\StudentBursaryEnrolment');
}
If what you want is to query all courses, from all enrollments, from all bursaries, from a students, then, unfortunately, you are one table too many from getting by with the Has Many Through relationship, because it supports only 3 tables.
Online, you'll find packages that you can import / or answers that you can follow to provide you more though of solutions, for example:
1) How to use Laravel's hasManyThrough across 4 tables
2) https://github.com/staudenmeir/eloquent-has-many-deep
Anyhow, bellow's something you can do to achieve that with Laravel alone:
// Eager loads bursaries, enrolments and courses, but, condition only courses.
$student = Student::with(['bursaries.enrolments.courses' => function($query) {
$query->where('course','LIKE','%B%');
}])->find(1);
$enrolments = collect();
foreach($student->bursaries as $bursary) {
$enrolments = $enrolments->merge($bursary->enrolments);
}
$courses = collect();
foreach ($enrolments as $enrolment) {
$courses = $courses->merge($enrolment->courses);
}
When you do $student->bursaries() instead of $student->bursaries, it returns a query builder instead of relationship map. So to go to enrolments() from bursaries() you need to do a bursaries()->get(). It should look like this.
$student->bursaries()->get()[0]->enrolments(), added the [0] because im using get(), you can use first() to avoid the [0]
$student->bursaries()->first()->enrolments()
But I'm not sure if it will suffice your requirement or not.

How to query from database when I have different foreign keys?

I am trying to query data from my database and pass the results to a view called events, the problem I have is that one of my queries will always return the same result because in the where condition the $events_id is the same always. Is there a better way to do the querying? A better logic?
This code is from my controller called EventController:
public function index()
{
$firm_id = DB::table('firms')->where('user_id', auth()->id())->value('id');
$events_id = DB::table('events')->where('firm_id', $firm_id)->value('id');
$events = DB::table('events')->where('firm_id', $firm_id)->get()->toArray();
$actual_events = DB::table('actual_events')->where('event_id', $events_id)->get()->toArray();
return view('events',['events' => $events,'actual_events' => $actual_events]);
}
Since the $events_id is the same every time, the $actual_events will only contain the first result.
The image I have uploaded shows the problem, my table's first three columns are fine. Starting from the fourth they contain repeated values:
As I guess, you need something like this:
$event_ids = DB::table('events')->where('firm_id', $firm_id)->pluck('id');
$actual_events = DB::table('actual_events')->whereIn('event_id', $event_ids)->get()->toArray();
or write about your problem in details and I will try to help you.
you just said that your tables have relation together.
in this case it's better you using the eloquent for that,
first you should type the relations in model of each table like this:
class User extends Authenticatable{
public function cities()
{
return $this->hasmany('App\City'); //you should type your relation
}
}
for relations you can use this link: laravel relationships
after that when you compact the $user variable to your view, you can use this syntax for getting the city value relation to this user: $user->cities;.

How to re-order an Eloquent collection?

I've got a collection of records retrieved via a relationship, and I'd like to order them by the created_at field. Is this possible in Eloquent?
Here is how I am retrieving the collection:
$skills = $employee->skills;
I'd like to order this $skills collection by their creation. I've tried $skills->orderBy('created_at', 'desc'); but the Collection class does not have an orderBy method.
I guess this problem is very simple and I'm missing something..
You can do this in two ways. Either you can orderBy your results while query, as in
$employee->skills()->orderBy('created_at', 'desc')->get();
OR
You can use sortBy and sortByDesc on your collection
The reason this is failing is that orderBy is a query method not a collection method.
If you used $skills = $employee->skills()->orderBy('created_at', 'desc')->get();, this would query the skills in the order you want.
Alternatively, if you already had a collection that you wanted to re-order, you could use the sortBy or sortByDesc methods.
You need to add the orderBy constraint on the query instead of the relationship.
For e.g,
$employees = Employee::where('salary', '>', '50000') // just an example
->with('skills') // eager loading the relationship
->orderBy('created_at', 'desc')
->get();
and then:
foreach($employees as $employee)
{
var_dump($employee->skill);
}
If you want the results to always be ordered by a field, you can specify that on the relationship:
Employee.php
public function skills() {
return $this->hasMany(Skills::class)->orderBy('created_at');
}
If you just want to order them sometimes, you can use orderBy(), but on the relationship, not the property:
$skills = $employee->skills()->orderBy('created_at')->get();
Collection has sortBy and sortByDesc
$skills = $skills->sortBy('created_at');
$skills = $skills->sortByDesc('created_at');
This Stackoverflow question askes how to order an Eloquent collection. However, I would like to propose a different solution to use instead given the example in the question. I would like to recommend to use an ordering on the query itself for performance reasons.
Like #Don't Panic proposes you can specify a default ordering on the relationship for great reusability convenience:
app/Models/Employee.php
public function skills() {
return $this->hasMany(Skills::class)->orderBy('created_at');
}
However, if you have already set an ordering on your query like we do in the code above, any additional orderings will be ignored. So that is a bummer if you want to use a different sorting in another situation. To overwrite this default ordering and re-order the query with a new ordering, one needs to use the reorder() method. For example:
// Get a Collections of Skill-models ordered by the oldest skill first.
$skills = $employee->skills()->reorder()->orderByDesc('created_at')->get();
// Same result as the previous example, but different syntax.
$skills = $employee->skills()->reorder()->oldest()->get();
// Or just give some arguments to the reorder() method directly:
$skills = $employee->skills()->reorder('created_at', 'desc')->get();

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