get one unique item from a laravel relationship

Question

i have a 1 to n relation ship between product and images and on images i have a field called color_id which has a 1 to n with images . now what i want to do is to call the product with images relationship like below :

  $relation = Product::with('images')->where('id',$product->id)->get();
        dd($relation);

now what want is to get 1 images from each color_id so for example if this product has 3 images with color_id of 1 , and 4 images with color_id of 2 .i want to get 1 images from each color . and here is the dd result of $relation in case needed .

^ Illuminate\Database\Eloquent\Collection {#945 ▼
  #items: array:1 [▼
    0 => Webkul\Product\Models\Product {#912 ▼
      #fillable: array:4 [▶]
      #connection: "mysql"
      #table: null
      #primaryKey: "id"
      #keyType: "int"
      +incrementing: true
      #with: []
      #withCount: []
      #perPage: 15
      +exists: true
      +wasRecentlyCreated: false
      #attributes: array:7 [▶]
      #original: array:7 [▶]
      #changes: []
      #casts: []
      #dates: []
      #dateFormat: null
      #appends: []
      #dispatchesEvents: []
      #observables: []
      #relations: array:1 [▼
        "images" => Illuminate\Database\Eloquent\Collection {#968 ▼
          #items: array:3 [▼
            0 => Webkul\Product\Models\ProductImage {#967 ▼
              +timestamps: false
              #fillable: array:4 [▶]
              #connection: "mysql"
              #table: null
              #primaryKey: "id"
              #keyType: "int"
              +incrementing: true
              #with: []
              #withCount: []
              #perPage: 15
              +exists: true
              +wasRecentlyCreated: false
              #attributes: array:6 [▶]
              #original: array:6 [▼
                "id" => 17
                "type" => null
                "path" => "product/39/y0ueAFEgscD9ZsVFg7nT2WPNsU6vDyXWqLVONa8L.jpeg"
                "product_id" => 39
                "product_color_id" => 3
                "product_size_id" => null
              ]
              #changes: []
              #casts: []
              #dates: []
              #dateFormat: null
              #appends: []
              #dispatchesEvents: []
              #observables: []
              #relations: []
              #touches: []
              #hidden: []
              #visible: []
              #guarded: array:1 [▶]
            }
            1 => Webkul\Product\Models\ProductImage {#970 ▼
              +timestamps: false
              #fillable: array:4 [▶]
              #connection: "mysql"
              #table: null
              #primaryKey: "id"
              #keyType: "int"
              +incrementing: true
              #with: []
              #withCount: []
              #perPage: 15
              +exists: true
              +wasRecentlyCreated: false
              #attributes: array:6 [▶]
              #original: array:6 [▼
                "id" => 23
                "type" => null
                "path" => "product/39/M9JTVsy2BtNp8LuUQh7cp17S5jN1ifOZ1P9WZk3h.jpeg"
                "product_id" => 39
                "product_color_id" => 2
                "product_size_id" => null
              ]
              #changes: []
              #casts: []
              #dates: []
              #dateFormat: null
              #appends: []
              #dispatchesEvents: []
              #observables: []
              #relations: []
              #touches: []
              #hidden: []
              #visible: []
              #guarded: array:1 [▶]
            }
            2 => Webkul\Product\Models\ProductImage {#969 ▼
              +timestamps: false
              #fillable: array:4 [▶]
              #connection: "mysql"
              #table: null
              #primaryKey: "id"
              #keyType: "int"
              +incrementing: true
              #with: []
              #withCount: []
              #perPage: 15
              +exists: true
              +wasRecentlyCreated: false
              #attributes: array:6 [▶]
              #original: array:6 [▼
                "id" => 24
                "type" => null
                "path" => "product/39/STA9sGKjWHWDn0wkmnVRqZYdI2adLE5qaIn7vyFQ.jpeg"
                "product_id" => 39
                "product_color_id" => 1
                "product_size_id" => null
              ]
              #changes: []
              #casts: []
              #dates: []
              #dateFormat: null
              #appends: []
              #dispatchesEvents: []
              #observables: []
              #relations: []
              #touches: []
              #hidden: []
              #visible: []
              #guarded: array:1 [▶]
            }
          ]
        }
      ]
      #touches: []
      +timestamps: true
      #hidden: []
      #visible: []
      #guarded: array:1 [▶]
    }
  ]
}

Answer 1

Try this

$relation =Product::with(array('images' => function($query) {
    $query->groupBy('product_color_id');
})->where('id',$product->id)->get();