Laravel亲戚用同步方法

Question

I try to store my products id and related them to each other just like when you attach tags to the post. (basically just store id of products nothing more)

Issue

when I try to save my product I get this error

SQLSTATE[42S22]: Column not found: 1054 Unknown column 'product_relative_id' in 'field list' (SQL: select `product_relative_id` from `product_relatives` where `product_id` = 46)

Codes

schema

public function up()
    {
        Schema::create('product_relatives', function (Blueprint $table) {
            $table->increments('id');
            $table->integer('product_id')->unsigned();
            $table->integer('relatives_id')->unsigned();
        });
        Schema::table('product_relatives', function (Blueprint $table) {
          $table->foreign('product_id')->references('id')->on('products');
          $table->foreign('relatives_id')->references('id')->on('products');
        });
    }

ProductRelative model

class ProductRelative extends Model
{
    public $timestamps = false;
    protected $table = 'product_relatives';

    public $fillable = ['product_id', 'relatives_id'];


    public function product()
    {
        return $this->belongsTo(Product::class, 'product_relatives');
    }
}

Product model

public function relatives()
  {
    return $this->belongsToMany(ProductRelative::class, 'product_relatives');
  }

Store method

//load other products in create page
public function create()
    {
        $relatives = Product::all();
        return view('admin.products.create', compact('relatives'));
    }

//storing new product
 public function store(Request $request)
    {
        //validation etc.
        $product->save();
        $product->relatives()->sync($request->relatives, false);
        return redirect()->route('products.show',$product->id);
    }

blade

{{ Form::label('relatives', 'Relative Products') }}
<select data-placeholder="Select a Relative product" class="form-control tagsselector" id="relatives" name="relatives[]" multiple="multiple">
  @foreach($relatives as $relative)
    <option value="{{ $relative->id }}">{{ $relative->title }}</option>
  @endforeach
</select>

Question

Why do I get the error and how to solve it?

UPDATE

I've changed my product model to the code below and it's working now.

public function relatives()
  {
    return $this->belongsToMany(ProductRelative::class, 'product_relatives', 'product_id', 'relatives_id');
  }

New Issue

Now that I can save my related products I have a hard time to return them in my view.

So far:

I added this code to my view function:

$relatives = ProductRelative::where('product_id', '=', $product->id)->get();

and added this code to my view:

@foreach($relatives as $relative)
  {{$relative}}
@endforeach

with that I can get result like:

{"id":3,"product_id":36,"relatives_id":2} {"id":5,"product_id":36,"relatives_id":25} 

but when I change my blade code to {{$relative->title}} it does not return anything.

How to fix that?

Answer 1

SOLVED

I changed my view codes to code below and it's working now:

$relatives = ProductRelative::where('product_id', '=', $product->id)
    ->join('products','products.id', '=', 'relatives_id')->get();

Hope it helps.