Laravel模型在单个查询中实现一对多

Question

i have this table structure, project has one to many relation with rewards , rewards and shipping has many to many relation with pivot table reward_ship .

projects       rewards         shipping       reward_ship
---------      --------        --------       ------------ 
id             id              id             id 
title          amount          location       reward_id
amount         project_id      name           ship_id

i am trying to extract one particular project details with all other associate tables data( rewards and shipping data using reward_ship table) in one query.

These is how i am trying

Projects Model

    class Rewards extends Model {
         public function projs(){
              return $this->hasMany('App\Rewards');
          }
         public function rewds(){
              return $this->belongsToMany('App\Shipping')
              ->withPivot('reward_ship', 'ship_id', 'reward_id');
         }
         public function shiplc(){
               return $this->belongsToMany('App\Rewards')
               ->withPivot('reward_ship', 'ship_id', 'reward_id');
         }
      }
class Rewards extends Model {
    public function proj() {
        return $this->belongsTo('App\Projects');
    }
}

Controller api class

Route::get('projects/{id}', function($id) {
$p = Projects::find($id);
$getd = Rewards::with('proj')
    ->where('rewards.project_id', '=', $p->id)
    ->get();
 }); 

it doesn't work. i search and tried many related model base query in larvel. i know my implementation are wrong. Please suggest me to work out.

Answer 1

You can use Laravel 5.5 new feature API Resources .

It helps you to format the output of objects such as models or collections, to display attributes and also relationships.

So, you could do something like this in your ItemResource:

    <?php

    namespace App\Http\Resources;

    use Illuminate\Http\Resources\Json\Resource;

    class Project extends Resource
    {
        /**
         * Transform the resource into an array.
         *
         * @param  \Illuminate\Http\Request
         * @return array
         */
        public function toArray($request)
        {
            return [
                'project_id' => $this->project_id,
                'title' => $this->title,
                'amount' => $this->amount,
                // To access relationship attributes:
                'rewards' => $this->rewards->load('shippings'),
            ];
        }
    }

Then in your controller, you just need to create a new Resource instance and pass the item object that you want to return:

use App\Http\Resources\Project as ProjectResource;

// some code

    /**
     * Show a single formatted resource.
     *
     * @param Project $project
     * @return ProjectResource
     */
    public function show($project)
    {
        return new ProjectResource($project);
    }

// the rest of your code

The output should be the expected.

Answer 2

class Project extends Model
{
    public function rewds()
    {
        return $this->hasMany('App\Rewards');
    }

    public function shiplc()
    {
        return $this->hasManyThrough('App\Shipping', 'App\Rewards');
    }
}

class Rewards extends Model
{
    public function shiplc()
    {
        return $this->belongsToMany('App\Shipping');

    }

    public function projs()
    {
        return $this->belongsTo('App\Project');
    }

}

class Shipping extends Model
{
    public function shiplc()
    {
        return $this->belongsToMany('App\Shipping');

    }
}

Route::get('projects/{id}', function($id) {
    $p = Projects::with(['rewds', 'shiplc'])->find($id);
});

Answer 3

Project.php

class Project extends Model {
    public function rewards() {
        return this->hasMany(Reward::class, 'project_id', 'id');
    }
}

Reward.php

class Reward extends Shipping {
    public function shipping(){
        return $this->belongsToMany(Shipping::class, 'reward_ship', 'reward_id', 'ship_id');
    }

    public function project(){
        return $this->belongsTo(Project::class);
    }
}

You can retrieve it like this:

$projectDetails = Project::where('id', $projectId)
                             ->with(['rewards', 'rewards.shipping'])->get();

Answer 4

You have to fix the relationships that you have :

Projects Model :

public function rewards(){
    return $this->hasMany('App\Rewards');
}

Rewards Model :

public function projects() {
    return $this->belongsTo('App\Projects');
}

public function shippings(){
    return $this->belongsToMany('App\Shipping','reward_ship', 'reward_id', 'ship_id');
}

Shipping model:

public function rewards(){
    return $this->belongsToMany('App\Rewards','reward_ship', 'ship_id', 'reward_id');
}

After that you can call the relationships in the controller to eager load the wanted elements like this :

$project = Projects::with('rewards.shippings')
                    ->where('id', $project_id)
                    ->get();

And in the view you can loop over the rewards then get the shippings like this :

@foreach ($project->rewards as $reward)
    <p>This is a reword {{ $reward->amount }}</p>
    @foreach ($reward->shippings as $shipping)
        <p>This is a shipping {{ $shipping->name }}</p>
    @endforeach 
@endforeach