i've 3 tables Branches,Subjects,Teachers
Branches and subjects already many to many.
i've CRUD for teacher,when i create teacher i insert info to user model to add new user with type teacher.
i want to make relation to allow me combine teachers/branches/subjects.
for example when i'm creating teacher i need to select branch/branches and subject/subjects that this teacher related to.
any hint allows me to do this ?
i it convert for you
If I get it right, you have established the many-to-many-relationships between every two of the three models
(Teacher, Branche & Subject).
Instead, you should establish the many-to many between any two models
of your choice and treat the third model as a pivot. For example:
Teacher.php
class Teacher extends Model
{
public function branches()
{
return $this->belongsToMany(Branche::class)->withPivot('subject');
}
}
Branche.php
class Branche extends Model
{
public function teachers()
{
return $this->belongsToMany(Teacher::class)->withPivot('subject');
}
}
view.blade.php
#foreach($teachers as $teacher)
#foreach($teacher->branches as $branc)
{{ $branc->name }} {{ $branc->pivot->subject }}
#endforeach
#endforeach
Related
In a project, let's say that we have Customers, and each customer can have one Voucher. The voucher, though, may be for a different thing for different customers - maybe for a Hote, a Car or a Flight.
We have a table of flight voucher codes, a table of hotel voucher codes and a table of car voucher codes.
When a customer is allocated a voucher, therefore, we allocated them the next code for the relevant thing that they're getting a voucher for. But rather than have multiple tables (customer_car_voucher, customer_hotel_voucher, and so on) I would rather have a Voucher table which is, in turn, linked to the relevant voucher type.
What I want to be able to do is just go $customer->voucher->code to get the relevant code, whether that be a flight, a hotel or a car. Other vouchers may be added at a later date, you see, for different things.
I think I can do this using morphable relationships - the voucher morphsTo car, hotel and flight, so within the the voucher table there is a "voucherable_type" and a "voucherable_id". But damned if I can get it to work.
Any help, please? Am I going about it wrong?
you arte right. and for a hint use:
public function customer()
{
return $this->belongsTo(Customer::class):
}
public function voucherable()
{
return $this->morphTo();
}
in voucher model.
and for each flight,car,hotel include:
public function voucher(){
return $this->morphOne(Voucher::class,'voucherable');
}
you can see Laravel morph relationship too for more help.
In Laravel's Eloquent ORM is used for morphable relationships.
First, create two Models AirVoucher and Voucher.
First, the AirVoucher model uses the following relationship.
public function voucher()
{
return $this->morphOne(Voucher::class, 'voucherable');
}
Second, the Voucher model uses the following relationship.
public function voucherable()
{
return $this->morphTo();
}
You can use the following Laravel official relationship document for more help.
Laravel Morph Relationships.
you must use laravel Polymorphic Relationships.
in Voucher model set this model as polymorph model(function name = modelname+"able"):
public function voucherable() \Illuminate\Database\Eloquent\Relations\MorphTo
{
return $this->morphTo();
}
then in Car model (or hotel/fight) set realation(function name= polymorph name):
if each car has one voucher, use morphOne:
public function files(): \Illuminate\Database\Eloquent\Relations\MorphOne
{
return $this->morphOne(Voucher::class, 'voucherable');
}
if each car has many voucher, use morphMany:
public function files(): \Illuminate\Database\Eloquent\Relations\MorphMany
{
return $this->morphMany(Voucher::class, 'voucherable');
}
Retrieving The Relationship
$car = Car::find(1);
$vocher = $car->voucher;
laravel docs
Is there a simple solution to detach (without deleting) all related models through a hasMany Relation on a model?
For example, I have two tables:
College (id, name)
Student (id, name, college_id(nullable) )
In the College model I define this relationship:
class College extends Model
{
public function students()
{
return $this->hasMany('App\Student','college_id','id');
}
}
What is the best way to detach all current College students from the College (i.e, get all the students of the college and set their college_id to null)?
Is there an easy way to detach all students from the College model using eloquent?
Something like
class College extends Model
{
...
public function detachAllStudents()
{
...
}
}
P.S. already have read this question Laravel hasMany detach, but get errors when I try to apply it to my application
Yes, you can detach all the college students as below. Actually, we already have the college_id in your students table and we have to make this college_id null somehow. This is not called detach in Eloquent. The word detach come when you have many to many relationships. So, let's just update the students and see if it works or not.
$college->students()->update(['college_id' => null);
So, you method can be completed as below:
public function detachAllStudents()
{
$college->students()->update(['college_id' => null]);
}
That's it!
Directly from the documentation https://laravel.com/docs/5.8/eloquent-relationships:
Toggling Associations
The many-to-many relationship also provides a toggle method which "toggles" the attachment status of the given IDs. If the given ID is currently attached, it will be detached. Likewise, if it is currently detached, it will be attached:
$user->roles()->toggle([1, 2, 3]);
Despite Imran answer perfectly fits this scenario I would add a more generic approach. Let's say $college respects an interface instead of an implementation, you wouldn't know the foreign key at run time.
<?php
use Illuminate\Database\Eloquent\Relations\HasMany;
interface HasStudents {
public function students(): HasMany;
}
class College extends Model implements HasStudents
{
public function students(): HasMany;
{
return $this->hasMany(Student::class, 'college_id', 'id');
}
}
function detachStudents(HasStudents $model): void {
$studentsRelationship = $model->students();
$studentsRelationship->update([
$studentsRelationship->getQualifiedForeignKeyName() => null
]);
}
detachStudents($college);
I'm learning Laravel and Laravel eloquent at the moment and now I try to solve a problem using relations in Laravel.
This is what I want to archive:
The database holds many sport clubs. A sport club has a lot of teams. Each team has games. The teams table has a column named club_id. Now I want to create Eloquent relations to get all games of a club.
Here is what I got so far:
Club model
id => PRIMARY
public function games()
{
return $this->hasMany('App\Models\Games')->whereHas('homeTeam')->orWhereHas('guestTeam');
}
Game model
home_id => FOREIGN KEY of team ; guest_id => FOREIGN KEY of team
public function homeTeam()
{
return $this->belongsTo('App\Models\Team','home_id')->where('club_id','=', $club_id);
}
public function guestTeam()
{
return $this->belongsTo('App\Models\Team','guest_id')->where('club_id','=', $club_id);
}
Team model
id => PRIMARY ; club_id => FOREIGN
In my controller all I want to do is Club::findOrFail($id)->games()
Executing the code above returns a SQL error that the games table does not have a column named club_id.
What is the correct way to create this kind of relation?
Thanks!
EDIT
Thanks to Nikola Gavric I've found a way to get all Games - but only where club teams are the home or away team.
Here is the relation:
public function games()
{
return $this->hasManyThrough('App\Models\Game','App\Models\Team','club_id','home_id');
}
How is it possible to get the games where the home_id OR the guest_id matches a team of the club? The last parameter in this function does not allow an array.
There is method to retrieve a "distant relationship with an intermediary" and it is called Has Many Through.
There is also a concrete example on how to use it which includes Post, Country and User, but I think it will be sufficient to give you a hint on how to create games relationship inside of a Club model. Here is a link, but when you open it, search for hasManyThrough keyword and you will see an example.
P.S: With right keys naming you could achieve it with:
public function games()
{
return $this->hasManyThrough('App\Models\Games', 'App\Models\Teams');
}
EDIT #01
Since you have 2 types of teams, you can create 2 different relationships where each relationship will get you one of the type you need. Like this:
public function gamesAsHome()
{
return $this
->hasManyThrough('App\Models\Games', 'App\Models\Teams', 'club_id', 'home_id');
}
public function gamesAsGuests()
{
return $this
->hasManyThrough('App\Models\Games', 'App\Models\Teams', 'club_id', 'guest_id');
}
EDIT #02
Merging Relationships: To merge these 2 relationships, you can use merge() method on the Collection instance, what it will do is, it will append all the records from second collection into the first one.
$gamesHome = $model->gamesAsHome;
$gamesGuests = $model->gamesAsGuests;
$games = $gamesHome->merge($gamesGuests);
return $games->unique()->all();
Thanks to #HCK for pointing out that you might have duplicates after the merge and that unique() is required to get the unique games after the merge.
EDIT #03
sortBy also offers a callable instead of a attribute name in cases where Collection contains numerical indexing. You can sort your Collection like this:
$merged->sortBy(function($game, $key) {
return $game->created_at;
});
When you define that Club hasMany games you are indicating that game has a foreign key called club_id pointing to Club. belongsTo is the same but in the other way. These need to be coherent with what you have on your database, that means that you need to have defined those keys as foreign keys on your tables.
Try this...
Club model
public function games()
{
return $this->hasMany('App\Models\Games');
}
Game model
public function homeTeam()
{
return $this->belongsTo('App\Models\Team','home_id');
}
public function guestTeam()
{
return $this->belongsTo('App\Models\Team','guest_id');
}
Your Query like
Club::where('id',$id)->has('games.guestTeam')->get();
I have four tables in database: groups, specialties, lessons, group_lesson. It's structures:
groups
id
specialty_id
name
specialties
id
name
lessons
id
specialty_id
group_lesson (UNIQUE INDEX lesson_id, group_id)
lesson_id
group_id
date
My models look like that for now:
class Group extends Eloquent {
public function specialty() {
return $this->belongsTo('Specialty');
}
}
class Lesson extends Eloquent {
public function specialty() {
return $this->belongsTo('Specialty');
}
}
class Specialty extends Eloquent {
public function lessons() {
return $this->hasMany('Lesson');
}
public function groups() {
return $this->hasMany('Group');
}
}
I need get additional fields in Group model look like that
Group - Eloquent model
name - string
lessons - collection of Lesson models of Group Specialty
date - date from group_lesson table
I've tried different relationships and combinations, but it's doesn't work. Please help me to write correct relationships.
You can use eager-loading to access relational data through relationships, and can even chain relationships further. As a rule of thumb, if you can draw a path to from 1 model to another through a relationship, you can eagerload all the relevant and relational data for that with chained eager-loads.
Laravel Eager Loading
As an example
$speciality_group = Speciality::with('group','lessons')->find($id);
Even though you are only getting a single instance of the speciality model, the related data is hasMany, meaning multiple records. You need to loop through these records using a foreach loop to access the relevant data for them, or alternitavely add additional closures in your initial query to load only a single related model.
foreach($speciality_group->group as $group)
{
echo $group->name;
}
You will need to do this for both instances where you want to display related information.
Table Structure:
games
id | name
awards
id | award name | game_id (fk)
Relationships
A game can have many awards.
An award has one game.
class Games extends Model
{
public $timestamps = false;
public function awards()
{
return $this->hasMany('award');
}
}
I need to get all the games out of my database. I do this using:
Game::all();
I then need to get all of the games out of my database but include data from the awards table.
I want to have an array which I can loop through to output the games, and if the game has an award - output this also.
What would be the correct eloquent statement?
Laravel's relations are brilliant for this kind of thing. Everything you have so far is on the correct path.
// Controller
public function index()
{
$games = Game::all();
return view('games.index', compact('games'));
}
// View
#foreach($games as $game)
{{ $game->name }}
#if(count($game->awards) > 0)
// Game has some awards, lets loop through them
#foreach($game->awards as $award)
{{ $award->name }}
#endforeach
#endif
#endforeach
Using the relation you've setup in your Game model you can instantly access the related data from other tables. Now each time you call $game->awards it will query the database, however using Laravel's Eager Loading you can pull all this information out at the same time rather than on demand.
// Controller
public function index()
{
$games = Game::with('awards')->get();
return view('games.index', compact('games'));
}
and by doing the exact same thing in the view you're no longer running a new query each time you want to get a games awards as they've already be fetched from the database. More on eager loading here http://laravel.com/docs/5.0/eloquent#eager-loading