跳过并限制嵌套数组元素 [英] Skip and Limit on nested array element

问题描述

我想对文档的嵌套数组中的分页应用跳过和限制，如何执行此[有效方式]

I want to apply skip and limit for paging in nested array of a document how can I perform this [Efficient Way]

我的文档的重印为

{
   "_id":"",
   "name":"",
   "ObjectArray":[{
       "url":"",
       "value":""
   }]
}

我想检索多个文档，每个文档都包含'n'个记录.

I want to retrieve multiple document and every document contain 'n' number of record.

我在查找查询中使用$in来检索基于_id的多条记录，但是如何在每个文档中获取一定数量的ObjectArray元素?

I am using $in in find query to retrieve multiple record on basis of _id but how can i get certain number of element of ObjectArray in every document?

推荐答案

您可以尝试这样-

db.collection.find({}, {ObjectArray:{$slice:[0, 3]}})

这将为您提供0..3

$slice:[SKIP_VALUE, LIMIT_VALUE]}

您的示例:-

db.collection.find({"_id":""}, {ObjectArray:{$slice:[0, 3]}})

此处是MongoDB Slice功能的参考. http://docs.mongodb.org/manual/reference/operator/projection/slice/

Here is the reference for MongoDB Slice feature. http://docs.mongodb.org/manual/reference/operator/projection/slice/

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