在MongoDB PHP中将数据类型从字符串更改为整数

<?php
// 连接到MongoDB数据库
$manager = new MongoDB\Driver\Manager("mongodb://localhost:27017");

// 获取集合对象
$collection = new MongoDB\Collection($manager, "mydb", "mycollection");

// 查询需要更改数据类型的文档
$filter = ["myfield" => ["$type" => "string"]];
$options = [];
$query = new MongoDB\Driver\Query($filter, $options);
$cursor = $manager->executeQuery("mydb.mycollection", $query);

// 遍历查询结果并更新数据类型
$bulk = new MongoDB\Driver\BulkWrite;
foreach ($cursor as $document) {
    $document->myfield = intval($document->myfield);
    $bulk->update(["_id" => $document->_id], ['$set' => ["myfield" => $document->myfield]]);
}

// 更新文档
$result = $manager->executeBulkWrite("mydb.mycollection", $bulk);

echo "数据类型已成功更改为整数。";
?>