通过 laravel 和 sql 分组的问题

Question

首先，我遇到了计算每天销售的产品的问题。在sql中我有查询

select product_name, sum(quantity) as quantity from invoice_product 
join invoices on invoices.id = invoice_product.invoice_id
join products on products.id = invoice_product.product_id
 where invoices.issued_at = '2019-05-16' 
 and products.`made_by_us` = 1
 group by product_name

它向我展示了有趣的信息，但我使用 product_name 来制作 group by 但我应该使用 product_id - 我也需要显示名称，但我不知道该怎么做。

其次，我想在 Laravel 中使用它，所以也许有人知道在 Eloquent 中可以使用它吗？

提前谢谢你:)

Answer 1

我会选择withCount() 和select(DB::raw())，像这样：

$products = Product::withCount(['invoices as quantity' => function ($query) {
    $query->select(DB::raw('sum(quantity)'));
}])->get();

然后，您可以像这样访问每个数量总和：

$quantity = $products->first()->quantity;

Answer 2

您需要更新模型关系才能实现这一目标。

型号：

InvoiceProduct模特

class InvoiceProduct extends Model
{
    protected $table = 'invoice_product';

    protected $guarded = [
        'id',
    ];
}

public function invoice()
{
    return $this->belongsTo('App\Invoice'); // Assuming `Invoice` Model is directly in app folder
}

public function product()
{
    return $this->belongsTo('App\Product'); // Assuming `Product` Model is directly in app folder
}

控制器：

$full_query = InvoiceProduct::whereHas('invoice', function ($query) {
   return $query->where('issued_at', '2019-05-16');
})->whereHas('product', function ($query) {
   return $query->where('made_by_us', 1);
});

$product_names = $full_query->get(['product_name']);
$total_quantities = $full_query->sum('quantity');