如何对文档中的内部数组进行排序？

Question

我正在通过 $push 在我的文档中的一个数组中进行“插入”，其中有一个字段日期，我想在使用 find() 时对其进行排序，但不对“_id”进行排序。如何按日期排序 (ordens.dtOrdem)？

    <?php

        $mongo = (new MongoDB\Client('mongodb://localhost:27017'))->Carteira;

        $collection = $mongo->ativo;

        /*First way that I've tried*/

        $result1 = $collection->find([].['ordens' => ['sort' => ['dtOrdem' => -1]]]);

   /*Second way that I've tried*/

   $result2 = $collection->find([],['ordens' => ['each' => ['ordens' => ['sort' => ['dtOrdem' = -1]]]]]);

?>

字段“ordens.dtOrdem”未按降序排序。

Answer 1

您不能在find().&nbsp;你有两个选择：您可以$sort在您的过程中指定一个操作，$push以确保您的元素按排序顺序添加到数组中。您可以使用聚合在检索时对数组进行排序。解决方案可能类似于以下内容（可能需要进行一些修改）：// Sorting on push.$collection->updateOne(&nbsp; &nbsp; [...],&nbsp; &nbsp; [ '$push' => [&nbsp; &nbsp; &nbsp; &nbsp; 'ordens' => [&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // You MUST include the $each operator here or this will not work.&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; '$each' => [&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; [ 'dtOrdem' => 5 ]&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; ],&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; // Where the magic happens, sorts in descending order.&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; '$sort'=> [ 'dtOrdem' => -1 ]&nbsp; &nbsp; &nbsp; &nbsp; ]&nbsp; &nbsp; ]]);// Sorting on retrieval.$collection->aggregate([&nbsp; &nbsp; [ '$unwind' => '$ordens' ],&nbsp; &nbsp; [ '$sort' => [&nbsp; &nbsp; &nbsp; &nbsp; '$ordens.dtOrdem' => -1&nbsp; &nbsp; ]],&nbsp; &nbsp; [ '$group' => [&nbsp; &nbsp; &nbsp; &nbsp; '_id' => '$_id',&nbsp; &nbsp; &nbsp; &nbsp; 'ordens' => [&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; '$push' => '$ordens'&nbsp; &nbsp; &nbsp; &nbsp; ]&nbsp; &nbsp; ]]]);