A contract has a representative (which is a user).
Currently I get this relationship with an belongsTo directly like this in my Contract model:
class Contract extends Model
{
public function representative()
{
return $this->belongsTo(User::class);
}
I would like to be able to retrieve this relationship through the organization_user table and retrieve the "position" attribute.
I think I should use the hasOneThrough relationship but I can't get what I'm looking for.
class Contract extends Model
{
public function representative()
{
return $this->hasOneThrough(User::class, OrganizationUser::class);
}
Not sure if you're in a position to change your DB structure, but it seems to me that your table contracts and organization_user are duplicating each other, storing the same data.
Would it make sense to leave only one table organization_user as a pivot table with the position?
Then you wouldn't need to make the big loop over few relationship to get the needed data.
Related
I want to display data in laravel.
This is the classrooms table:
This is the students table:
this is the classroom_student table :
I expect a result like this:
With class from the classroom table, year from the student table (the year the student was created), and data from the student table (data for each month, sample data:[2,4,6] means Jan: 2, Feb: 4, Mar: 6). I don't know how to make it. Can you help me? thank you
You need to setup a many to many relationship both of your models (classroom model and student model. It will look something like this:
class Classroom extends Model {
public function students(){
return $this->hasMany(Student:class, 'student_id');
}
}
class Student extends Model {
public function classrooms(){
return $this->hasMany(Classroom:class, 'classroom_id');
}
}
Here is also a reference to laravel docs for the exact solution:
https://laravel.com/docs/8.x/eloquent-relationships#many-to-many
You Should use HasMany Relation in both Models and while fetching data call this relation function to get data related to other model and set expected title for those data in Transformer.
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
I have Order model with another relation OrderPhoto:
public function OrderPhoto()
{
return $this->hasMany('App\OrderPhoto');
}
In turn OrderPhoto model has relation:
public function Photo()
{
return $this->belongsToMany('App\Photo');
}
So, how to get data from OrderModel with related data from third model Photo?
I guess this:
Order::with("OrderPhoto.Photo")->get();
to retrieve only data from Photo model for each Order
So, each Order has some OrderPhotos. Relationship is one to many.
But one item from OrderPhotos is related with primary key from table Photos. It is one to one relation.
My result query should be:
select `photos`.*, `ordersphoto`.`Orders_Id` from `photos` inner join `ordersphoto` on `ordersphoto`.`Photos_Id` = `photos`.`Id` where `ordersphoto`.`Orders_Id` in (1);
How to use hasManyThrough for this query?
Just having a quick look at your relationships it looks like you could create a hasManyThrough relationship on the order Model.
public function Photo {
return $this->hasManyThrough('App\OrderPhoto', 'App\Photo')
}
You may need to add the table keys to make it work
This will allow you to do:
Order::with("Photo")->get();
You can see more details here https://laravel.com/docs/5.5/eloquent-relationships#has-many-through
Update
Try this
public function Photo {
return $this->hasManyThrough('App\Photo', 'App\OrderPhoto', 'Order_id', 'Photos_id', 'id', 'id')
}
It is a little hard to get my head around your DB structure with this info but you should hopefully be able to work it out. This may also help
https://laravel.com/api/5.7/Illuminate/Database/Eloquent/Concerns/HasRelationships.html#method_hasManyThrough
I have 3 databases:
Routes:
id
name
Rates:
Id
Route_id
Car_id
Cars:
id
name
My model for routes
public function rates()
{
return $this->hasMany('App\Rate', 'route_id');
}
My model for rates
public function car() {
return $this->belongsTo('App\Car','car_id');
}
Now I need to access the car relation, but when I do
return $this->route->with('from','to','rates.car')->paginate(74);
I get null for the car relation
{"id":1,"from_id":1,"to_id":2,"distance":400,"created_at":null,"updated_at":null,"from":{"id":1,"name":"\u0410\u043a\u043a\u043e","created_at":null,"updated_at":null,"lat":32.93310000000000314912540488876402378082275390625,"long":35.0827000000000026602720026858150959014892578125},"to":{"id":2,"name":"\u0410\u0440\u0430\u0434","created_at":null,"updated_at":null,"lat":31.261399999999998300381776061840355396270751953125,"long":35.21490000000000009094947017729282379150390625},"rates":[{"id":1,"route_id":1,"car_id":1,"rate":1123,"night_rate":1391,"car":null},{"id":5551,"route_id":1,"car_id":2,"rate":1123,"night_rate":1391,"car":null},{"id":11101,"route_id":1,"car_id":3,"rate":1123,"night_rate":1391,"car":null},{"id":16651,"route_id":1,"car_id":4,"rate":1123,"night_rate":1391,"car":null},{"id":22201,"route_id":1,"car_id":5,"rate":1123,"night_rate":1391,"car":null},{"id":27751,"route_id":1,"car_id":6,"rate":1123,"night_rate":1391,"car":null},{"id":33301,"route_id":1,"car_id":7,"rate":1123,"night_rate":1391,"car":null},{"id":38851,"route_id":1,"car_id":8,"rate":1123,"night_rate":1391,"car":null}]},
From my understanding you are trying to access a Car model through a Route model.
A couple of things I noticed that should help you find a solution.
First off I think the inverse relation you are supposed to use the belongToMany() function instead.
public function car() {
return $this->belongsToMany('App\Car','Rates'); // Perhaps call the table something like routes_cars to more clearly define it's a pivot table
}
Next I see you are trying to use model functions within the context of $this(). I assume you are doing this in your model? That logic should be in a controller, that might cause some undesired results but I'm not entirely sure. Also it looks like your parameters are incorrect when using with(). You use the function name that you defined in belongsToMany()
App/Route::with('car')->paginate(74);
With the correct relationships setup you rarely need to worry about the pivot table. If you are going to add extra information in the pivot table there are laravel functions to help you do that in the documentation.
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.