以下是收集内容的示例:
- 博客作者 *
[
{
_id: ObjectId(...),
posts: [
{
"platform": "instagram"
},
{
"platform": "tiktok"
},
],
full_name: "John Doe",
},
{
_id: ObjectId(...),
posts: [
{
"platform": "youtube"
},
{
"platform": "tiktok"
},
],
full_name: "Mamed Mamedov"
}
]
作为聚合的结果,我想得到这样的结果:
[
{
_id: ObjectId(...),
platforms: ["instagram", "tiktok"],
full_name: "John Doe",
},
{
_id: ObjectId(...),
platforms: ["youtube", "tiktok],
full_name: "Mamed Mamedov"
}
]
(List posts
字段中的平台数量)
到目前为止,我甚至不确定mongodb中是否有现成的方法。
1条答案
按热度按时间myzjeezk1#
您可以使用$reduce轻松完成此操作:
example