node.js - MongoError $in 需要一个数组

Question

我正在尝试从数组中获取数据，并希望将其传递给 $in 运算符内的查找查询。但它给出了一个错误说

$in needs an array

const fileIds = _.get(result, 'files', []);
console.log(fileIds);
db.collection('files').find({_id: {$in: fileIds}}).toArray((err, files) => 

{
    // some statements....
}

这是 console.log(fileIds) 的输出

{ '0': 5a8f24ab281bd22cd940530b, '1': 5a8f24ab281bd22cd940530c }

在标记重复之前我已经看过这篇文章。

How to return the ObjectId or _id of an document in MongoDB? and error "$in needs an array"

但这些没有帮助。所以如果有人知道答案请帮忙。提前致谢。

Answer 1

Please do this

here i have use Object.values which is supported by node version 6.9 or 8 you can create array by another method

  const fileIds = _.get(result, 'files', []);

    db.collection('files').find({_id: {$in: Object.values(fileIds)}}).toArray((err, files) => 

    {
        // some statements....
    }