Laravel 集合 group by
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Laravel collection group by
提问by Hardist
I have a search function to search for expenses by a certain date, month, string, whatever. It returns a collection:
我有一个搜索功能，可以按特定日期、月份、字符串等搜索费用。它返回一个集合：
So far so good. I can display all returned Expenses. Now, what I want to do is, display also a total expense count and total amount, grouped by the description_id. If I simply do $result->groupBy('description_id), I just get a set of collections, from which I can display the total count and total amount, but not the name of the description. Example of what I want:
到现在为止还挺好。我可以显示所有返回的Expenses. 现在，我想要做的是，还显示总费用计数和总金额，按description_id. 如果我只是这样做$result->groupBy('description_id)，我只会得到一组集合，从中我可以显示总计数和总金额，但不能显示描述的名称。我想要的例子：
Grouped Results (By Expense):
Description Name: <-- Issue displaying this
Total Expenses: 3
Total Amount: 53444
The description name can only be obtained via the relation between Expenseand Description. An Expense belongsTo a description.
描述名只能经由之间的关系来获得Expense和Description。费用属于描述。
Is it at all possible to achieve what I want, when working with my collection, or should I perform a seperate query for those results? (undesired)
在处理我的收藏时，是否有可能实现我想要的结果，或者我应该对这些结果执行单独的查询？（不想要的）
回答by Oluwatobi Samuel Omisakin
If you eager-load description, then you can group the resulting collection by the nested object of the collection. So you may have:
如果您预先加载description，那么您可以通过集合的嵌套对象对结果集合进行分组。所以你可能有：
$expenses = Expenses::with('description')->get(); //collection
Then group it:
然后分组：
$grouped = $expenses->groupBy('description.name');
//or
$grouped = $expenses->groupBy('description_id');
Then you can use the name of description, accessing it, say we need the first group, and the first expense in the group,
然后你可以使用description的名字，访问它，说我们需要第一组，以及组中的第一笔费用，
$description_name = $grouped
->first() //the first group
->first() //the first expense in group
->description //the description object
->name //the name
This is just a little proof that you can get the name of the related model in the collection and use it to solve your question.
这只是一个小证明，您可以在集合中获取相关模型的名称并使用它来解决您的问题。
