laravel belongsToMany code example

Example 1: one to many laravel

For example, a blog post may have an infinite number of comments. And a single
comment belongs to only a single post  

class Post extends Model
{
    public function comments()
    {
        return $this->hasMany('App\Models\Comment');
    }
}

class Comment extends Model
{
    public function post()
    {
        return $this->belongsTo('App\Models\Post');
    }
}

Example 2: laravel detach

// Detach a single role from the user...
$user->roles()->detach($roleId);

// Detach all roles from the user...
$user->roles()->detach();

Example 3: whereHas site:https://laravel.com/docs/

use Illuminate\Database\Eloquent\Builder;

// Retrieve posts with at least one comment containing words like code%...
$posts = Post::whereHas('comments', function (Builder $query) {
    $query->where('content', 'like', 'code%');
})->get();

// Retrieve posts with at least ten comments containing words like code%...
$posts = Post::whereHas('comments', function (Builder $query) {
    $query->where('content', 'like', 'code%');
}, '>=', 10)->get();

Example 4: laravel belongs to

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class Phone extends Model
{
    /**
     * Get the user that owns the phone.
     */
    public function user()
    {
        return $this->belongsTo('App\Models\User');
    }
}

Example 5: laravel pivot table model

/*Model - Service*/
public function customer(){
    return $this->belongsToMany('customer')->withPivot(
        'start_date',
        'stop_date',
        'rem_date',
        'due_date',
        'status'
        );
}

/*Model - customer*/
public function services(){
    return $this->belongsToMany('Service')->withPivot(
        'start_date',
        'stop_date',
        'rem_date',
        'due_date',
        'status'
        );
}

////These following relations didnt workout
/*Model - custserv*/ //uses the pivot table customer_service//
public function staff(){
    return $this->belongsToMany('Staff');
}

/*Model - Staff*/
public function custservs(){
    return $this->belongsToMany('Custserv');
}

/*schema for pivot table 'staff' and 'Custserv' */
Schema::create('customer_service_user', function(Blueprint $table)
    {
        $table->increments('id');
        $table->integer('customer_service_id')->unsigned()->index();
        $table->foreign('customer_service_id')->references('id')->on('customer_service')->onDelete('cascade');
        $table->integer('staff_id')->unsigned()->index();
        $table->foreign('staff_id')->references('id')->on('staff')->onDelete('cascade');
        $table->timestamps();
    });

Example 6: add data to laravel many to many relationship

1. $user->roles()->attach($roleId);

2. you may also pass an array of additional data to be inserted 
$user->roles()->attach($roleId, ['expires' => $expires]);

3. // Detach a single role from the user...
$user->roles()->detach($roleId);

4. // Detach all roles from the user...
$user->roles()->detach();

5. Any IDs that are not in the given array will be removed from the intermediate
	table
$user->roles()->sync([1, 2, 3]);

6. If you need to update an existing row in your pivot table, you may use 
  updateExistingPivot method. This method accepts the pivot record foreign 
  key and an array of attributes to update:

$user->roles()->updateExistingPivot($roleId, $attributes);