One-To-One Eloquent Relationship functions - php

There is something I miss in the eloquent one-to-one relationship:
class MeetingTest extends Model
{
protected $table = 'meeting_tests';
public function meeting() {
return $this->belongsTo('App\Meeting','meeting_id','id');
}
public function observation() {
return $this->hasOne('App\Observation','meeting_test_id','id');
}
public function activity() {
return $this->hasOne('App\TestActivity','activity_id','id');
}
}
The Observation Class is
class Observation extends Model
{
protected $table = 'observations';
public function meetingTest() {
return $this->belongsTo('App\MeetingTest','meeting_test_id','id');
}
}
If I run php artisan tinker and
$mtn = App\MeetingTest::create();
$mtn->save();
$ob = App\Observation::create();
$ob->save;
$mtn->observation()->save($ob);
At this point inside the Observation record I can see the meeting_test_id filled with the correct id of the meetingTest, but if I try:
$mtn->observation
it gives me null; and in the Database there is no observation ID in the observation_id field;
this is the migration:
Schema::create('meeting_tests', function (Blueprint $table) {
$table->increments('id');
$table->integer('meeting_id')->unsigned();
$table->integer('observation_id')->unsigned()->nullable();
$table->integer('activity_id')->unsigned()->nullable();
$table->timestamps();
});
I don't understand what is not correct.

I can see observation_id and activity_id in your meeting_tests table, which makes records in this table the owned side of one-to-one/one-to-many relation. Therefore, both activity and observation relations in MeetingTest should return $this->belongsTo instead of $this->hasOne

Related

Laravel 7 One To Many Relations?

Below are all of the models, migrations and controller.
Donation Model
class Donation extends Model
{
protected $guarded =[];
public function users(){
return $this->hasMany(User::class);
}
public function items(){
return $this->belongsTo(DonationItems::class);
}
}
Donation Items Model:
class DonationItems extends Model
{
protected $guarded=[];
public function donation(){
return $this->hasMany(Donaition::class);
}
}
Donation Items Migration:
public function up()
{
Schema::create('donation_items', function (Blueprint $table) {
$table->id();
$table->string('category');
$table->timestamps();
});
}
Donation Migration:
public function up()
{
Schema::create('donations', function (Blueprint $table) {
$table->id();
$table->string('item');
$table->unsignedInteger('user_id');
$table->unsignedInteger('donation_item_id');
$table->timestamps();
});
}
In my controller I want to access the items as follows:
$don = Donation::all();
$don->items;
But I'm unable to achieve this.
Its not working because laravel follows one rule for relationships:
Remember, Eloquent will automatically determine the proper foreign key column on the Comment model. By convention, Eloquent will take the "snake case" name of the owning model and suffix it with _id. So, for this example, Eloquent will assume the foreign key on the Comment model is post_id.
So you can try by supplying local and foreign id
So it would look something like this
Donation Model
class Donation extends Model
{
protected $guarded =[];
public function users(){
return $this->hasMany(User::class);
}
public function items(){
return $this->belongsTo(DonationItems::class, 'donation_item_id', 'id');
}
}
Donation Items Model:
class DonationItems extends Model
{
protected $guarded=[];
public function donation(){
return $this->hasMany(DonationItems::class, 'id', 'donation_item_id');
}
}
I am writing from my head you might need to swap local and foreign ID's

i want to return the projects of specific user?

I want to return the projects of the authenticated user, but am not getting any. I know the records exist in the database.
This is my model Project:
public function users(){
return $this->hasMany(User::class);
}
this is my model User:
public function projects(){
return $this->hasMany(Projet::class,'user_id');
}
and this is the controller function :
public function projetuser(){
$user = User::find(auth()->user()->id);
return $user->projects;
}
and this my user_projet migration:
public function up()
{
Schema::create('user_projet', function (Blueprint $table) {
$table->bigIncrements('id');
$table->unsignedBigInteger('projet_id');
$table->foreign('projet_id')->references('id')->on('projets')->onDelete('cascade');
$table->unsignedBigInteger('user_id');
$table->foreign('user_id')->references('id')->on('users')->onDelete('cascade');
$table->string('membre')->nullbale();
$table->timestamps();
});
}
You are defining a many-to-many relationship incorrectly. Use belongsToMany() instead of hasMany(). Because your pivot table name is not standard (it should be alphabetic order projet_user) you need to include it in the relationship definition as well.
<?php
use Illuminate\Database\Eloquent\Model;
class Projet extends Model
{
public function users()
{
return $this->belongsToMany(User::class, 'user_projet');
}
}
class User extends Model
{
public function projets(){
return $this->belongsToMany(Projet::class, 'user_projet');
}
}
Now in your controller you can do this:
public function projetuser(){
return auth()->user->projets;
}
Your question seems to vary between "projet" and "project." I assumed "projet" was the correct spelling, but try to keep this consistent.
Please note also the typo in your migration: nullbale.

How to make a one to one eloquent relation in Laravel?

I created my migration by using the artisan command
php artisan make:model Player -m
My migration then looked like this:
public function up()
{
Schema::create('players', function (Blueprint $table) {
$table->bigIncrements('id');
$table->unsignedBigInteger('user_id')->index();
$table->foreign('user_id')->references('id')->on('users')->onDelete$
$table->string('username');
$table->timestamps();
});
}
Which left me no errors when I ran
php artisan migrate
I then updated my Player model App/Player.php to include the fillables and one to one relation
class Player extends Model
{
protected $fillable = ['user_id', 'username'];
public function user()
{
return $this->belongsTo('App\User');
}
}
I then ran the Tinker artisan and my output when I try to access the player model is this
>>> User::find(1)->player;
=> null
What am I missing?
Have you done the reverse connection?
Here is the Relation Code
public function player()
{
return $this->hasOne(Player::class);
}
public function user()
{
return $this->belongsTo('App\User','id' */foreign_key */ ,'user_id'*/owner_key*/);
}
i think you forgot to specify the owner_id,
if you dont specify the owner_key of belongsTo the default belongsTo getting is the model id.
User Model
public function player(){
return $this->hasOne('App\Player');
}
Player Model
public function user(){
return $this->belongsTo('App\User');
}

laravel eloquent relationship hierarchy

I seem to be having a problem understanding this hierarchical relationship.
Farm > Fields > Shepherds > Sheep
It seems a pretty straightforward hierarchy - Farm hasMany fields, field hasMany shepherds, shepherd hasMany sheep.
Sheep belong to a shepherd, shepherds belongs to fields, fields belong to farms.
I have defined this model relationships thus:
class Sheep extends Model {
protected $fillable ['name'];
public function shepherd() {
return $this->belongsTo('App\Shepherd');
}
}
class Shepherd extends Model {
protected $fillable ['name'];
public function field() {
return $this->belongsTo('App\Field');
}
public function sheep() {
return $this->hasMany('App\Sheep');
}
}
class Field extends Model {
protected $fillable ['name'];
public function farm() {
return $this->belongsTo('App\Farm');
}
public function shepherd() {
return $this->hasMany('App\Shepperd');
}
}
class Farm extends Model {
protected $fillable ['name'];
public function field() {
return $this->hasMany('App\Field');
}
}
public function up()
{
Schema::create('farms', function (Blueprint $table) {
$table->increments('id');
$table->string('name');
});
}
public function up()
{
Schema::create('fields', function (Blueprint $table) {
$table->increments('id');
$table->integer('farm_id');
$table->string('name');
});
}
public function up()
Schema::create('shepherds', function (Blueprint $table) {
$table->increments('id');
$table->integer('field_id');
$table->string('name');
});
}
public function up()
Schema::create('sheep', function (Blueprint $table) {
$table->increments('id');
$table->integer('shepherd_id');
$table->string('name');
});
}
I would expect to be able to save each model in the following manner.
$farm = new App\Farm;
$farm->name = 'West Farm';
$field = new App\Field;
$field->name = 'The orchard';
$shepherd = new App\Shepherd;
$shepherd->name = 'Jason';
$sheep = new App\Sheep;
$sheep->name = 'Sean';
$farm->save();
$farm->field()->save($farm);
$farm->field->shepherd()->save($shepherd);
$farm->field->shepherd->sheep()->save($sheep);
But it does not work. Once I get to $farm->field->shepherd()->save($shepherd); the process breaks down. I would appreciate some assistance in the correct manner of saving using the relationships between all the tables.
I'm pulling my hair out trying to understand this, so any help would be greatly appreciated.
thanks
Your code breaks here:
$farm->field->shepherd()->save($shepherd);
Farms have many fields, so when you reference $farm->field, you're getting a collection of Field object, not just a single Field object.
To make it work, you need to either reference $farm->field[0]
$farm->field[0]->shepherd()->save($shepherd);
or just use the $field object you created before:
$field->shepherd()->save($shepherd);
I'd also suggest to use plural names for your hasMany relations (fields, sheeps, etc.) - this way you'll always remember that the referenced fields refer to a collection, not a single object

Laravel 5.1 Multiple Many to Many Relationship on the Same Model

I seen to of got tangled in Laravel's ORM with the following:
Scenerio: All Users have a Watchlist, the Watchlist contains other Users.
I can't seem the get the relationships to work correctly as they are cyclical, so far I have the following:
class UserWatchlist extends Model
{
protected $table = 'UserWatchlist';
public function Owner() {
return $this->belongsTo('App\User');
}
public function WatchedUsers() {
return $this->hasMany('App\User');
}
}
Schema::create('UserWatchlist', function (Blueprint $table) {
$table->increments('id');
$table->integer('user_id')->unsigned();
$table->foreign('user_id')->references('id')->on('Users')->onDelete('cascade');
$table->integer('watched_id')->unsigned();
$table->foreign('watched_id')->references('id')->on('Users')->onDelete('cascade');
$table->timestamps();
});
class User extends Model
{
public function Watchlist() {
return $this->hasOne('App\UserWatchlist');
}
public function WatchedBy() {
return $this->belongsToMany('App\UserWatchlist');
}
}
It is not pulling through the correct in formation i'm expecting. Am I missing something fundamental?
Since UserWatchlist is a pivot table, i suppose you are facing a many to many relationship with both the elements of the relation being the same model (User)
If that is the case, you should not build a model for the pivot table UserWatchlist but all you have to do is to set the relation between the users through the pivot table:
class User extends Model
{
//get all the Users this user is watching
public function Watchlist()
{
return $this->belongsToMany('User', 'UserWatchlist', 'user_id', 'watched_id' );
}
//get all the Users this user is watched by
public function WatchedBy()
{
return $this->belongsToMany('User', 'UserWatchlist', 'watched_id', 'user_id' );
}
}
Check here for more info on many-to-many relationship

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