How wherePivot() actually works internally in laravel 5? - php

How wherePivot() actually works internally in laravel 5 ?
For Example I was practicing by watching a tutorial and the teacher was using wherePivot() for construing relationship:
public function friendsOfMine(){
return $this->belongsToMany('Chatty\Models\User','friends','user_id','friend_id');
}
public function friendOf(){
return $this->belongsToMany('Chatty\Models\User','friends','friend_id','user_id');
}
public function friends(){
return $this->friendsOfMine()->wherePivot('accepted',true)->get()->merge($this->friendOf()->wherePivot('accepted',true)->get());
}

Thanks Guys .. but I think i found my answer
A pivot table is a database table that only exists to serve a many-to-many relationship. Say you have a table “customer” and a table “drinks”. If you want to know which customer ordered which drink you have to create a pivot table customer_drinks(customer_id, drink_id).
Define Pivot table
class Customer extends \Eloquent {
public function drinks()
{
return $this->belongsToMany('Drink', 'customer_drinks', 'customer_id', 'drink_id');
}
}
Create a Record
$customer = Customer::find($customer_id);
$customer->drinks()->attach($drink_id); //this executes the insert-query
Remove record from pivot Table
$customer = Customer::find($customer_id);
$customer->drinks()->detach($drink_id); //this executes the delete-query on the pivot table

Related

Many to Many Relationship with 2 FK referencing from same PK Laravel 8

Hello I am working on a Laravel project, that i have to assign for one Mentorship «Mentoria», one Mentor «Mentor» and one student «Mentorando». The data of the student and the mentor, came from the Users table (i assigned them roles, using Spatie) , and the other table is called «Mentoria» Since there exists a many to many relation i created the pivot table that is called «utilizador_mentoria» and has ID_Mentor, ID_Mentorando (both are FKs coming from the users table),and ID_mentoria (coming from Mentoria table). I defined both models as this:
User Model:
protected $casts = [
'email_verified_at' => 'datetime',
];
public function interesses(){
return $this->belongsToMany(AreaInteresse::class, 'utilizador_interesse', 'id_utilizador', 'id_interesse');
}
public function mentorias(){
return $this->belongsToMany(Mentoria::class, 'utilizador_mentoria', 'id_mentoria', 'id_mentorando', 'id_mentor');
}
ps: I have interesses function with other model, that is working properly. my problem is with the «mentorias»
Mentoria Model:
public function users(){
return $this->belongsToMany(User::class, 'utilizador_mentoria','id_mentor','id_mentorando','id_mentoria');
}
With this, i am trying to get the data from all Mentorias, and the data of the Mentor that is assigned to that that Mentoria, however when i am doing this code on the controller, the data coming from the user appears empty, despite i have the DB filled with data. I tried a echo for testing, and it only shows the data of the Mentoria, and where it should appear the data of the Mentor assigned to that MEntoria, it is empty
the code from the controller:
public function mentorias(){
$mentorias = Mentoria::with('users')->get();
echo $mentorias;
return view('admin/mentorias/admin_mentorias', ['mentorias' => $mentorias]);
}
the output of the echo
[{"id":2,"titulo":"teste","titulo_en":"test","descricao":"fe","descricao_en":"ewfwe","created_at":"2021-12-28T01:32:10.000000Z","updated_at":"2021-12-28T01:32:10.000000Z","users":[]}]
Since as i already said, i already used data from 2 tables with Many to Many relation, however with only 1 FK per PK, and it is working properly, i have no idea why it is not working this way . I already checked for similar questions, however with no luck
Edit:
For testing purposes, i removed the column of one of the two FK that reference from the same PK, and i managed to work, however with this aditional FK i am not managing to make it work . I believe that the problem is with the relation, in the models but i have no idea how to make it work
I rearranged the funcitons in the models as they are now
User Model:
public function mentorias(){
return $this->belongsToMany(Mentoria::class, 'utilizador_mentoria', 'id_mentor', 'id_mentorando', 'id_mentoria');
}
Mentoria Model:
public function users(){
return $this->belongsToMany(User::class, 'utilizador_mentoria','id_mentoria','id_mentorando','id_mentor');
i also tried to took out,example «id_entorando» from the main () and put it after with the «withPivot» method, but it still didn't worked
I don't know if I properly understood the problem but your relationship is not a single "many to many", but two "one to many". In the end I'll show why it's convenient to consider them as two separated relationships.
First: If a user can have multiple mentorships but a mentorship can have only 1 mentor (which I suppose is what's happening), then you should use the "hasMany/belongsTo" pair:
User Model:
public function mentorias(){
return $this->hasMany(Mentoria::class);
}
Mentoria Model:
public function user(){
return $this->belongsTo(User::class);
}
Second: Complete the scenario with the other relationship bewteen the mentorship and the students:
User Model:
public function mentorias(){
return $this->hasMany(Mentoria::class);
}
public function mentoria(){
return $this->belongsTo(Mentoria::class);
}
Mentoria Model:
public function user(){
return $this->belongsTo(User::class);
}
public function mentorandos(){
return $this->hasMany(User::class);
}
There should be a user_id column in the mentorias table that represents the Teacher which the mentorships belong to:
Schema::table('mentorias', function (Blueprint $table) {
$table->unsignedInteger('user_id')->nullable();
});
And there should also be a mentor_id column in the users table that represents the mentorship which the students belong to:
Schema::table('users', function (Blueprint $table) {
$table->unsignedInteger('mentoria_id')->nullable();
});
Third: This double representation of the User Model could lead to confusion, since two different objects (teacher and student) are using the same model but are not meant to have both relationships simultaneously: A teacher shouldn't be mentored and a student shouldn't lead mentorships.
In order to roperly manage Teachers and Students and prevent confusion, you could create additional models that inherit the User Model and define the relationships for them (instead of the User Model), so you can limit the fields and the relationships for each one of them.
User Model:
// No relationships
Teacher Model:
// Extending from User allows you to have all the User Model functionality
class Teacher extends User
{
public function mentorias(){
return $this->hasMany(Mentoria::class)->with('students');
}
}
Student Model:
// Extending from User allows you to have all the User Model functionality
class Student extends User
{
public function mentoria(){
return $this->belongsTo(Mentoria::class)->with('teacher');
}
}
Mentoria Model:
public function teacher(){
return $this->belongsTo(Teacher::class);
}
public function students(){
return $this->hasMany(Student::class);
}
In the end, you'll have all the info you need from the mentorship when you call objects like this:
Teacher::with('mentorias')->get();
// This will show the Teacher's mentorias and the students in each one
Student::with('mentoria')->get();
// This will show the Student's mentoria and its teacher
Mentoria::with(['teacher', 'students'])->get();
// This will show the teacher and the students for each mentoria

How to join two tables with a pivot table using Laravel?

I have these three tables:
tbl_lista_contactabilidad tbl_equipo_postventaatc users
------------------------- ----------------------- -----
id id id
usuarios_id asesor_id name
tbl_lista_contactabilidad.usuarios_id should be related with tbl_equipo_postventaatc.asesor_id. asesor_id should be the "pivot" between tbl_lista_contactabilidad.usuarios_id and users.id to make the relation.
I want to make this relation so I tried to do this relation in this way (I will put only the relation of the model)
Tbl_Lista_Contactabilidad (Model 1)
public function postventaatc(){
return $this->belongsTo('App\Models\Tbl_EquipoPostventaatc','usuarios_id');
}
Tbl_Equipo_Postventaatc (Model 2) -> This should be the pivot model
public function contactabilidad(){
return $this->hasMany('App\Models\Tbl_Lista_Contactabilidad','usuarios_id');
}
public function user(){
return $this->belongsTo('App\Models\User','asesor_id');
}
User (Model 3)
public function postventaatc(){
return $this->hasMany('App\Models\Tbl_Lista_Postventaatc','asesor_id');
}
EXAMPLE:
As you see in the image... if I relate usuarios_id with users directly I will get another name and I don't want that... I want the relation just like in the image
A pivot table is a structure used to join two separate models together with a single relationship. This is called a many-to-many relationship in Eloquent.
From what you've described, this is not the case here. Rather, it looks like a has-many-through relationship.
If I'm understanding correctly, your relationships should look like this:
<?php
namespace App\Models;
use Illuminate\Database\Eloquent\Model;
class Tbl_Lista_Contactabilidad extends Model {
protected $table = 'tbl_lista_contactabilidad';
public function postventaatc() {
return $this->belongsTo(Tbl_EquipoPostventaatc::class, 'usuarios_id');
}
}
class Tbl_EquipoPostventaatc extends Model {
protected $table = 'tbl_equipo_postventaatc';
public function contactabilidad() {
return $this->hasMany(Tbl_Lista_Contactabilidad::class, 'usuarios_id');
}
}
class User extends Model {
public function postventaatc() {
return $this->belongsTo(Tbl_EquipoPostventaatc::class, 'asesor_id');
}
public function contactabilidad() {
return $this->hasManyThrough(Tbl_Lista_Contactabilidad::class, Tbl_EquipoPostventaatc::class, 'asesor_id', 'usuarios_id');
}
}
Obviously this is easier for a native English speaker, but I cannot stress how much easier this would be if you were following the Laravel rules around naming your models, tables, and columns. Why does usuarios_id column relate to a table called tbl_equipo_postventaatc? Why use asesor_id instead of user_id? 🤷🏽‍♂️ Those names have nothing to do with each other, and make it hard to figure out what is going on.

Laravel - Many to Many on pivot table with Eloquent

I have three table which I wanna associate. Shipment_methods, Ship_companies and Payment_methods.
Relations:
Shipment_methods <- pivot1 -> Ship_companies
pivot1 <- pivot2 -> Payment_methods
Well, what I wanna do is e.g. ShipmentMethod_A is attached to ShipCompany_B and for this record (from pivot1) I wanna attach record from Payment_method table through pivot2 table.
ShipmentMethod Model:
public function ship_companies()
{
return $this->belongsToMany(ShipCompany::class, 'shipment_methods_ship_companies', 'shipment_method_id', 'ship_company_id')->withPivot('price_kc', 'price_ha');
}
ShipCompany Model:
public function shipment_methods()
{
return $this->belongsToMany(ShipCompany::class, 'shipment_methods_ship_companies', 'ship_company_id', 'shipment_method_id');
}
What I need to do is I wanna retrieve all Payments for ShipCompany of specific ShipmentMethod like
ShipmentMethods->ship_companies->pivot->payments_methods
Thanx.
I think best way is for you to have a Model that extend Pivoted class for you pivot1. the pivot1 should have id column to use in pivot2. so the code should be like this,
ShipmentMethod Model:
public function ship_companies()
{
return $this->belongsToMany(ShipCompany::class, 'shipment_methods_ship_companies', 'shipment_method_id', 'ship_company_id')->using('App\pivot1')->withPivot('id','price_kc', 'price_ha');
}
note that I have put id in withPrivot and chain using() method
your pivot1 model should be like this,
pivot1 Model:
use Illuminate\Database\Eloquent\Relations\Pivot;
class pivot1 extends Pivot
{
public function Payment_methods()
{
return $this->belongsToMany(Payment_methods::class, 'pivot2_table_name', 'pivot1_id', 'payment_method_id');
}
}
and at the end you can do like this to save to pivot2
ShipmentMethods->ship_companies->pivot->payments_methods()->sync([payment_method_ids])
as all pivot relationship return a collection of array note that you need to loop ShipmentMethods->ship_companies relationship to get to pivot relationship.
Hope this helps!

Eloquent belongsTo relationships

Not sure why it's now working for me.
I have two tables
events
- id
selections
- id
- event_id
From my Event model I want to relationship selections
class Event extends Model
{
...
public function selections()
{
return $this->belongsTo(Selection::class, 'event_id', 'id');
}
}
My problem is that $event->selections relationship is not working. Keep getting null back.
With the database schema, it is hasMany relation instead.
public function selections()
{
return $this->hasMany(Selection::class, 'event_id', 'id');
}
See One to many relationship in documentation.

Make a simple join to a reference table with Laravel 5.1 Eloquent

I have a simple join to make, but I can't do it.
I have a tournament that has a categoryId field in the table.
The table TournamentLevel is a 10 entry table.
So I would like to be able to retrieve level->name with Eloquent.
I tried to do the following:
In Tournament, I tried to define a hasOne relationship:
class Tournament extends Model
{
....
public function level()
{
return $this->hasOne('App\TournamentLevel');
}
But then, Eloquant is looking for tourmanent_id inside of TournamentLevel Table
So I tried the opposite,
In Model TournamentLevel:
class TournamentLevel extends Model
{
...
public function tournament()
{
return $this->belongsTo('App\Tournament');
}
}
And tried to reach :
tournament->level->name
but without success
It seems pretty elementary, but I can't do it... Any idea???

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