restore composer.json, add mysqli extension

app/Models/Characteristic.php

@@ -0,0 +1,55 @@
+<?php
+
+namespace App\Models;
+
+use Illuminate\Database\Eloquent\Model;
+
+class Characteristic extends Model
+{
+    /**
+     * @var array
+     */
+    protected $guarded = ['id'];
+
+    /**
+     * @var array
+     */
+    protected $casts = [
+        'category_id' => 'integer',
+        'name' => 'array',
+        'type' => 'string',
+        'options' => 'array',
+        'filter' => 'boolean'
+    ];
+
+    /**
+     * @return \Illuminate\Database\Eloquent\Relations\BelongsTo
+     */
+    public function category()
+    {
+        return $this->belongsTo(Category::class);
+    }
+
+    /**
+     * @return \Illuminate\Database\Eloquent\Relations\BelongsToMany
+     */
+    public function product()
+    {
+        return $this->belongsToMany(Product::class,'characteristics_products')->withPivot('value');
+    }
+
+    public function values()
+    {
+        return $this->belongsToMany(Product::class,'characteristics_products')
+            ->withPivot('value')
+            ->select('product_id', 'value');
+    }
+
+    /**
+     * @return \Illuminate\Database\Eloquent\Relations\BelongsToMany
+     */
+    public function filter()
+    {
+        return $this->belongsToMany(Category::class, 'characteristics_categories');
+    }
+}