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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")
}
]
}
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