以排序形式从多个文档返回内部数组元素 [英] Returning inner array elements from multiple document in sorted form
本文介绍了以排序形式从多个文档返回内部数组元素的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我的收藏集是这样的，我试图按日期的排序顺序获取特定blog_id的所有评论列表.
hyy there, my collection goes like this and I am trying to get all comments list of particular blog_id in sorted order of date.
[
{
"_id" : ObjectId("565f0f5d77f0c7bd11bbadd8"),
"blog_id" : ObjectId("56587befdb7224110f007233"),
"comments" : [
{
"user_id" : ObjectId("562fa014888806820e21e0df"),
"user_full_name" : "Niroj Paudel",
"comment" : "pradip is bhole baba",
"_id" : ObjectId("565f0f5d77f0c7bd11bbadd9"),
"dt" : ISODate("2015-12-02T15:33:49.578Z")
},
{
"user_id" : ObjectId("562fa014888806820e21e0df"),
"user_full_name" : "Niroj Paudel",
"comment" : "honkog pokhara... he he ha ha",
"_id" : ObjectId("565f1034fd07cbfc1129db0b"),
"dt" : ISODate("2015-12-02T15:37:24.581Z")
}
],
"record_count" : 2,
"__v" : 0
}
{
"_id" : ObjectId("565efa37635f09900d21a339"),
"blog_id" : ObjectId("56587befdb7224110f007233"),
"comments" : [
{
"user_id" : ObjectId("562fa014888806820e21e0df"),
"user_full_name" : "Niroj Paudel",
"comment" : "wat a nice car wow",
"_id" : ObjectId("565efa37635f09900d21a33a"),
"dt" : ISODate("2015-12-02T14:03:35.289Z")
},
{
"user_id" : ObjectId("562fa014888806820e21e0df"),
"user_full_name" : "Niroj Paudel",
"comment" : "love is life budikhola ma dives",
"_id" : ObjectId("565efa76635f09900d21a33b"),
"dt" : ISODate("2015-12-02T14:04:38.661Z")
},
{
"user_id" : ObjectId("562fa014888806820e21e0df"),
"user_full_name" : "Niroj Paudel",
"comment" : "bholi ajaya ko bihe",
"_id" : ObjectId("565efaa0635f09900d21a33c"),
"dt" : ISODate("2015-12-02T14:05:20.847Z")
},
{
"user_id" : ObjectId("562fa014888806820e21e0df"),
"user_full_name" : "Niroj Paudel",
"comment" : "manish is nice",
"_id" : ObjectId("565efb17635f09900d21a33d"),
"dt" : ISODate("2015-12-02T14:07:19.704Z")
},
{
"user_id" : ObjectId("562fa014888806820e21e0df"),
"user_full_name" : "Niroj Paudel",
"comment" : "niroj is cool",
"_id" : ObjectId("565efd53c22dddc80e8f461c"),
"dt" : ISODate("2015-12-02T14:16:51.730Z")
},
{
"user_id" : ObjectId("562fa014888806820e21e0df"),
"user_full_name" : "Niroj Paudel",
"comment" : "ramesh is cool",
"_id" : ObjectId("565f0d376d82e24c11f6c0d1"),
"dt" : ISODate("2015-12-02T15:24:39.010Z")
}
],
"record_count" : 6,
"__v" : 0
}
]
我想按日期的降序列出特定blog_id的所有评论，如下所示
I want to list all comments of particular blog_id in descending order of date like below
[
{
"user_id" : ObjectId("562fa014888806820e21e0df"),
"user_full_name" : "Niroj Paudel",
"comment" : "wat a nice car wow",
"_id" : ObjectId("565efa37635f09900d21a33a"),
"dt" : ISODate("2015-12-02T14:03:35.289Z")
},
{
"user_id" : ObjectId("562fa014888806820e21e0df"),
"user_full_name" : "Niroj Paudel",
"comment" : "love is life budikhola ma dives",
"_id" : ObjectId("565efa76635f09900d21a33b"),
"dt" : ISODate("2015-12-02T14:04:38.661Z")
},
{
"user_id" : ObjectId("562fa014888806820e21e0df"),
"user_full_name" : "Niroj Paudel",
"comment" : "bholi ajaya ko bihe",
"_id" : ObjectId("565efaa0635f09900d21a33c"),
"dt" : ISODate("2015-12-02T14:05:20.847Z")
},
{
"user_id" : ObjectId("562fa014888806820e21e0df"),
"user_full_name" : "Niroj Paudel",
"comment" : "manish is nice",
"_id" : ObjectId("565efb17635f09900d21a33d"),
"dt" : ISODate("2015-12-02T14:07:19.704Z")
},
{
"user_id" : ObjectId("562fa014888806820e21e0df"),
"user_full_name" : "Niroj Paudel",
"comment" : "niroj is cool",
"_id" : ObjectId("565efd53c22dddc80e8f461c"),
"dt" : ISODate("2015-12-02T14:16:51.730Z")
},
{
"user_id" : ObjectId("562fa014888806820e21e0df"),
"user_full_name" : "Niroj Paudel",
"comment" : "ramesh is cool",
"_id" : ObjectId("565f0d376d82e24c11f6c0d1"),
"dt" : ISODate("2015-12-02T15:24:39.010Z")
}
{
"user_id" : ObjectId("562fa014888806820e21e0df"),
"user_full_name" : "Niroj Paudel",
"comment" : "pradip is bhole baba",
"_id" : ObjectId("565f0f5d77f0c7bd11bbadd9"),
"dt" : ISODate("2015-12-02T15:33:49.578Z")
},
{
"user_id" : ObjectId("562fa014888806820e21e0df"),
"user_full_name" : "Niroj Paudel",
"comment" : "honkog pokhara... he he ha ha",
"_id" : ObjectId("565f1034fd07cbfc1129db0b"),
"dt" : ISODate("2015-12-02T15:37:24.581Z")
}
]
我如何在mongooes或mongodb中做到这一点
how Can I do this in mongooes or mongodb
我尝试过
BlogComments.aggregate([
{$match:{blog_id:blogId}},
{
$group:{
_id:statusId,comment_count:{$sum:"$record_count"},comments:{$push:"$comments"}
}
},
{ "$unwind": "$comments" },
{ "$unwind": "$comments" },
{ "$group": {
"_id": statusId,
"comment_count": { "$first": "$comment_count" },
"comments": { "$addToSet": "$comments" }
}},
{ $sort: {'comments._id': 1}}
]);
此查询提供了来自多个文档的注释和所有相关注释，但注释按随机顺序排列. $ sort无法为我正常工作
This query gives comment and all associated comments from the multiple document but comments are in random order. $sort is not properly working for me
谢谢.
推荐答案
Jorin，
尝试一下:
db.comments.aggregate(
[
{$match: {blog_id: ObjectId("56587befdb7224110f007233")}}, //match blogid
{"$unwind": "$comments"}, //unwind the comments array
{$sort: {"comments.dt": 1}}, //sort the comment documents by date
{
"$group": {
"_id": '$blog_id', //group comment documents by blog_id
"comments": {
"$push": "$comments" //push comments of same blog_id into an array
}
}
}])
根据您的样本数据，输出将为:
Based upon your sample data the output will be:
{
"_id" : ObjectId("56587befdb7224110f007233"),
"comments" : [
{
"user_id" : ObjectId("562fa014888806820e21e0df"),
"user_full_name" : "Niroj Paudel",
"comment" : "wat a nice car wow",
"_id" : ObjectId("565efa37635f09900d21a33a"),
"dt" : ISODate("2015-12-02T14:03:35.289Z")
},
{
"user_id" : ObjectId("562fa014888806820e21e0df"),
"user_full_name" : "Niroj Paudel",
"comment" : "love is life budikhola ma dives",
"_id" : ObjectId("565efa76635f09900d21a33b"),
"dt" : ISODate("2015-12-02T14:04:38.661Z")
},
{
"user_id" : ObjectId("562fa014888806820e21e0df"),
"user_full_name" : "Niroj Paudel",
"comment" : "bholi ajaya ko bihe",
"_id" : ObjectId("565efaa0635f09900d21a33c"),
"dt" : ISODate("2015-12-02T14:05:20.847Z")
},
{
"user_id" : ObjectId("562fa014888806820e21e0df"),
"user_full_name" : "Niroj Paudel",
"comment" : "manish is nice",
"_id" : ObjectId("565efb17635f09900d21a33d"),
"dt" : ISODate("2015-12-02T14:07:19.704Z")
},
{
"user_id" : ObjectId("562fa014888806820e21e0df"),
"user_full_name" : "Niroj Paudel",
"comment" : "niroj is cool",
"_id" : ObjectId("565efd53c22dddc80e8f461c"),
"dt" : ISODate("2015-12-02T14:16:51.730Z")
},
{
"user_id" : ObjectId("562fa014888806820e21e0df"),
"user_full_name" : "Niroj Paudel",
"comment" : "ramesh is cool",
"_id" : ObjectId("565f0d376d82e24c11f6c0d1"),
"dt" : ISODate("2015-12-02T15:24:39.010Z")
},
{
"user_id" : ObjectId("562fa014888806820e21e0df"),
"user_full_name" : "Niroj Paudel",
"comment" : "pradip is bhole baba",
"_id" : ObjectId("565f0f5d77f0c7bd11bbadd9"),
"dt" : ISODate("2015-12-02T15:33:49.578Z")
},
{
"user_id" : ObjectId("562fa014888806820e21e0df"),
"user_full_name" : "Niroj Paudel",
"comment" : "honkog pokhara... he he ha ha",
"_id" : ObjectId("565f1034fd07cbfc1129db0b"),
"dt" : ISODate("2015-12-02T15:37:24.581Z")
}
]
}
这篇关于以排序形式从多个文档返回内部数组元素的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
查看全文
