Laravel Model with Two Primary Keys update [duplicate]

Question

I'm trying to update Model which has two primary keys.

Model

namespace App;  use Illuminate\Database\Eloquent\Model;  class Inventory extends Model {     /**      * The table associated with the model.      */     protected $table = 'inventories';      /**      * Indicates model primary keys.      */     protected $primaryKey = ['user_id', 'stock_id']; ... 

Migration

Schema::create('inventories', function (Blueprint $table) {     $table->integer('user_id')->unsigned();     $table->integer('stock_id')->unsigned();     $table->bigInteger('quantity');      $table->primary(['user_id', 'stock_id']);      $table->foreign('user_id')->references('id')->on('users')         ->onUpdate('restrict')         ->onDelete('cascade');     $table->foreign('stock_id')->references('id')->on('stocks')         ->onUpdate('restrict')         ->onDelete('cascade'); }); 

This is code which should update Inventory model, but it doesn't.

$inventory = Inventory::where('user_id', $user->id)->where('stock_id', $order->stock->id)->first(); $inventory->quantity += $order->quantity; $inventory->save(); 

I get this error:

Illegal offset type 

I also tried to use updateOrCreate() method. It doesn't work (I get same error).

Can anyone tell how Model with two primary key should be updated?

Answer 1

I've run into this problem a couple of times. You need to override some properties:

protected $primaryKey = ['user_id', 'stock_id']; public $incrementing = false; 

and methods (credit):

/**  * Set the keys for a save update query.  *  * @param  \Illuminate\Database\Eloquent\Builder  $query  * @return \Illuminate\Database\Eloquent\Builder  */ protected function setKeysForSaveQuery(Builder $query) {     $keys = $this->getKeyName();     if(!is_array($keys)){         return parent::setKeysForSaveQuery($query);     }      foreach($keys as $keyName){         $query->where($keyName, '=', $this->getKeyForSaveQuery($keyName));     }      return $query; }  /**  * Get the primary key value for a save query.  *  * @param mixed $keyName  * @return mixed  */ protected function getKeyForSaveQuery($keyName = null) {     if(is_null($keyName)){         $keyName = $this->getKeyName();     }      if (isset($this->original[$keyName])) {         return $this->original[$keyName];     }      return $this->getAttribute($keyName); } 

Remember this code needs to reference Eloquent Builder class with

use Illuminate\Database\Eloquent\Builder; 

I suggest putting those methods in a HasCompositePrimaryKey Trait so you can just use it in any of your models that need it.