[英]Mongoose / mongoDb search where I need values of unpopulated property
所以我正在用 mongodb / mongoose 進行搜索。 我有一個 post 文檔,這個 post 文檔有一個 comments 屬性,它由 comment IDS 組成。 此搜索的目標是收集今天添加了評論的所有用戶帖子。
我找不到任何帖子,因為我正在搜索 comments.created_date 並且此屬性尚不存在,因為我在 comments 屬性的數組中只有評論 IDS。
我如何“填充”這個數組,以便我可以找到添加了評論的帖子?
代碼:首先我們生成這一天開始的Date對象。 然后我們搜索帖子。 在這里,我談論的是第一個 $or 案例:comments.created_date 不起作用,因為此屬性由評論 ID 組成。 如何獲取用戶今天發表評論的帖子?
// Generate the actual time
const todayForEvent = moment().startOf('day')
.utc().toDate();
const posts = await Post.find({
$or: [{
// From this user...
$and: [
// Find normal posts that has comments (recent interactions)
{ _posted_by: userId },
{ comments: { $exists: true, $ne: [] } },
{ 'comments.created_date': { $gte: todayForEvent } }
]
}, {
$and: [
// Find tasks due to today
{ 'task._assigned_to': userId },
{ 'task.due_to': { $in: [today, tomorrow] } }
]
}, {
$and: [
// Find events due to today
{ 'event._assigned_to': userId },
{ 'event.due_to': { $gte: todayForEvent, $lt: todayPlus48ForEvent } }
]
}]
})
.sort('event.due_to task.due_to -comments.created_date')
.populate('_posted_by', 'first_name last_name profile_pic')
.populate('task._assigned_to', 'first_name last_name')
.populate('event._assigned_to', 'first_name last_name')
.populate('_group', 'group_name group_avatar')
.populate('_liked_by', 'first_name last_name');
console.log('POSTS', posts);
模特兒
const mongoose = require('mongoose');
const { Schema } = mongoose;
const PostSchema = new Schema({
content: {
type: String,
trim: true
},
_content_mentions: [{
type: Schema.Types.ObjectId,
ref: 'User'
}],
type: {
type: String,
required: true,
enum: ['normal', 'event', 'task']
},
_liked_by: [{
type: Schema.Types.ObjectId,
ref: 'User'
}],
comments_count: {
type: Number,
default: 0
},
comments: [{
type: Schema.Types.ObjectId,
ref: 'Comment'
}],
_group: {
type: Schema.Types.ObjectId,
ref: 'Group',
required: true
},
_posted_by: {
type: Schema.Types.ObjectId,
ref: 'User',
required: true
},
task: {
due_to: {
type: String,
default: null
},
_assigned_to: {
type: Schema.Types.ObjectId,
ref: 'User'
},
status: {
type: String,
enum: ['to do', 'in progress', 'done']
}
},
event: {
due_to: {
type: Date,
default: null
},
_assigned_to: [{
type: Schema.Types.ObjectId,
ref: 'User'
}]
},
created_date: {
type: Date,
default: Date.now
},
files: [{
orignal_name: {
type: String,
default: null
},
modified_name: {
type: String,
default: null
}
}]
});
const Post = mongoose.model('Post', PostSchema);
module.exports = Post;
評論模型
const mongoose = require('mongoose');
const moment = require('moment');
const { Schema } = mongoose;
const CommentSchema = new Schema({
content: {
type: String,
trim: true
},
_content_mentions: [{
type: Schema.Types.ObjectId,
ref: 'User'
}],
created_date: {
type: Date,
default: moment().utc().toDate()
},
_commented_by: {
type: Schema.Types.ObjectId,
ref: 'User',
required: true
},
_post: {
type: Schema.Types.ObjectId,
ref: 'Post',
required: true
}
});
const Comment = mongoose.model('Comment', CommentSchema);
module.exports = Comment;
由於您必須使用 comments created_date
字段過濾文檔,因此您必須使用 comment 集合而不是 post 開始聚合,並使用$lookup
聚合加入posts
const todayForEvent = moment().startOf('day').utc().toDate()
db.comments.aggregate([
{ "$match": { "created_date": { "$gte": todayForEvent } }},
{ "$lookup": {
"from": "posts",
"localField": "_id",
"foreignField": "comments",
"as": "posts"
}},
{ "$unwind": "$posts" },
{ "$replaceRoot": { "newRoot": "$posts" }}
])
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