从Laravel中的分页结果集中获取不同的行

Question

I have created the following for a product catelog/lister:

public function index($type_id = null) {
    $filters = $sort = array();
    if (isset($type_id)) {
        $filters['type'] = $type_id;
    } else {
        $filters['type'] = Input::get('type');
    }
    $filters['search'] = Input::get('search');
    $filters['brand'] = Input::get('brand');

    $sort['sort'] = Input::get('sort');
    $sort['sortdir'] = Input::get('dir');

    $productsPaginated = $this->fetchProducts($filters, $sort);

    return View::make('products.products', array(
                'productsList' => $productsPaginated
                    )
    );
}

public function fetchProducts($filters, $sorts, $perpage = 2) {
    print_r($filters);
    $Product = Product::query();
    if (!empty($filters['search']))
        $Product->where('name', 'LIKE', '%' . $filters['search'] . '%');
    if (isset($filters['type']))
        $Product->where('type_id', $filters['type']);
    if (isset($filters['brand']))
        $Product->where('brand_id', $filters['brand']);

    if (isset($sorts['sort']))
        $Product->orderBy($sorts['sort'], $sorts['sortdir']);

    $Product = $Product->paginate($perpage);
    return $Product;
}

Which works well so far.

I am now trying to create some filters so a user can further filter the results.

How can I access and determine distinct rows based on a column in:

$productsPaginated = $this->fetchProducts($filters, $sort);

?

Answer 1

The groupBy method not only exists on the query builder but also on the collection class. (which will be returned when calling paginate)

Take a look at the source on github

So add an argument to your function and use groupBy

public function fetchProducts($filters, $sorts, $perpage = 2, $groupBy = null) {
// code omitted for brevity
    $Product = $Product->paginate($perpage);
    if($groupBy){
        $Product = $Product->groupBy($groupBy);
    }
    return $Product;
}

Update

Then there's the lists function that works on collections as well as on query builders...

$Product->lists('column-name');

Update 2

I was curious so I did some testing and a found something very weird and I have no idea if its a bug or a feature I don't understand

When calling groupBy the collection returned has actually only one item (index "") and this item contains an array of the "original" items. So to make lists work. I found this workaround

$Product = $Product->groupBy($groupBy);
$Product = new Collection($Product[""]); // \Illuminate\Support\Collection
$Product = $Product->lists('column-name');