Laravel - Group By 和 Key By 在一起
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Laravel - Group By & Key By together
提问by dev7
Assuming I have the following MySQL tables to represent pricebooks, items and the relationship between them:
假设我有以下 MySQL 表来表示价格手册、项目以及它们之间的关系：
item - item_id|name|...etc
pricebook - pricebook_id|name|...etc
and the following pivot table
和以下 pivot table
pricebook_item - pricebook_id|item_id|price|...etc
I have the correlating Eloquent models: Pricebook, Itemand a repository named PricebookDatato retrieve the necessary information.
我有相关的 Eloquent 模型：Pricebook，Item以及一个命名PricebookData为检索必要信息的存储库。
Within the PricebookDatarepository, I need to get the pricebook data grouped by pricebook id and then keyed by item_id for easy access on client side.
在PricebookData存储库中，我需要获取按 pricebook id 分组的 pricebook 数据，然后按 item_id 键入以便在客户端轻松访问。
If I do:
如果我做：
Pricebook::all()->groupBy('pricebook_id');
I get the information grouped by the pricebook_idbut inside each pricebook the keys are simple numeric index (it arrives as js array) and not the actual product_id. So when returning to client side Javascript, the result arrives as the following:
我得到了按 分组的信息，pricebook_id但在每个价格手册中，键是简单的数字索引（它作为 js 数组到达）而不是实际的 product_id。因此，当返回客户端 Javascript 时，结果如下：
pricebookData: {1: [{}, {}, {}...], 2: [{}, {}, {}...]}
The problem with the prices arriving as array, is that I can not access it easily without iterating the array. Ideally I would be able to receive it as:
价格作为数组到达的问题是，如果不迭代数组，我就无法轻松访问它。理想情况下，我可以将其接收为：
pricebookData: {1: {1001:{}, 1002: {}, 1003: {}}, 2: {1001:{}, 1002: {}, 1003: {}}}
//where 1001, 1002, 1003 are actual item ids
//with this result format, I could simply do var price = pricebookData[1][1001]
I've also tried the following but without success:
我也尝试了以下但没有成功：
Pricebook::all()->keyBy('item_id')->groupBy('pricebook_id');
Pricebook::all()->keyBy('item_id')->groupBy('pricebook_id');
The equivalent of what I am trying to avoid is:
我试图避免的等价物是：
$prices = Pricebook::all();
$priceData = [];
foreach ($prices as $price)
{
if (!isset($priceData[$price->pricebook_id]))
{
$priceData[$price->pricebook_id] = [];
}
$priceData[$price->pricebook_id][$price->item_id] = $price;
}
return $priceData;
I am trying to find a pure elegant Eloquent/Query Builder solution.
我试图找到一个纯粹优雅的 Eloquent/Query Builder 解决方案。
回答by alepeino
I think what you want is
我想你想要的是
Pricebook::all()
->groupBy('pricebook_id')
->map(function ($pb) { return $pb->keyBy('item_id'); });
You first group by Pricebook, then each Pricebook subset is keyed by item_id. You were on the right track with
您首先按 Pricebook 分组，然后每个 Pricebook 子集以 item_id 为键。你在正确的轨道上
Pricebook::all()->keyBy('item_id')->groupBy('pricebook_id');
unfortunately, as it is implemented, the groupByresets previous keys.
不幸的是，随着它的实施，groupBy重置以前的键。
Update:
更新：
Pricebook::all()->keyBy('item_id')->groupBy('pricebook_id', true);
(groupBysecond parameter $preserveKeys)
（groupBy第二个参数$preserveKeys）
