Laravel/雄辩的hasMany关系sum()

本文介绍了Laravel/雄辩的hasMany关系sum()的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我不知道如何急于加​​载一个关系列的总和.

I can't figure out how to eager load a sum of a relationships columns.

数据库(简体)如下；

Database (simplified) is as follows;

表格

PRODUCT PRODUCT_VARIATIONS *ID* *ID* *NAME* *NAME* *AVAILABLE_STOCK*

我的恋爱关系设置如下；

I have my relationships set up as follows;

public function variations() { return $this->hasMany('Product_variation'); }

加载所有产品时，我希望能够看到该产品附加到产品对象本身的所有库存的总和.

When loading all Products I want to be able to see the SUM of all stock for that product attached to the product object itself.

产品可能有很多变化.

我可以退还产品附带的全部个人"变体(请参见下文)

I can return the entire INDIVIDUAL variations attached to the products (See Below)

$products = Product::with('variations')->paginate(15);

但是我只想返回所有带有一个简单整数的产品，其中要考虑所有变化，以显示其available_stock计数.

but I just want to return all the products with a simple integer showing their available_stock count taking into account all variations.

我希望能够输入

@foreach ($products as $product) $product->available_stock // Returns INT @endforeach

推荐答案

好的，谢谢你的回答@joseph，现在我知道我在追赶大雁.

OK, thanks for your answer @joseph, now I know I was on a wild goose chase.

使用无吸引力的foreach解决了问题

Solved the problem with an unattractive foreach

$products = Product::with('variations')->remember(2)->paginate(15); foreach ($products as $product) { $i = 0; foreach ($product->variations as $variation) { $i = $i + $variation->available_stock; } unset($product->variations); $product->available_stock = $i; }