在猫鼬中为朋友模式建模? [英] Modelling for friends schema in mongoose?

问题描述

当我位于其他用户个人资料上时，如何对猫鼬模式进行建模以获取这三个按钮?

How do I model my mongoose schema to get these three buttons when I am on the other users profile?

1. 添加朋友
2. 已请求
3. 朋友

我的用户架构

const schema = new Mongoose.Schema({
  firstName: { type: String, default: '', trim: true },
  lastName: { type: String, default: '', trim: true },
}, { timestamps: true })

我无法为此找到正确的建模...并且还请在建模后建议汇总...

I could not find the correct modelling for this... And also please suggest the aggregation after modelling...

推荐答案

所以最后我做到了，我认为这可能是用mongodb和mongoose做到的最好方法

So Finally I made it and I think it is probably the best way to do it with mongodb and mongoose

1..为用户创建模型.

1. Create a model for users.

    var Schema = mongoose.Schema
    const usersSchema = new Schema({
      firstName: { type: String, required: true },
      lastName: { type: String, required: true },
      friends: [{ type: Schema.Types.ObjectId, ref: 'Friends'}]
    }, {timestamps: true})
    module.exports = mongoose.model('Users', usersSchema)

2..为拥有枚举值的朋友创建一个模型，该枚举用于接受，拒绝，待处理和请求.

2. Create a model for friends having enums for accepted, rejected, pending and requested.

    const friendsSchema = new Schema({
      requester: { type: Schema.Types.ObjectId, ref: 'Users'},
      recipient: { type: Schema.Types.ObjectId, ref: 'Users'},
      status: {
        type: Number,
        enums: [
            0,    //'add friend',
            1,    //'requested',
            2,    //'pending',
            3,    //'friends'
        ]
      }
    }, {timestamps: true})
    module.exports = mongoose.model('Friends', friendsSchema)

3.现在api调用->假设我们有两个用户UserA和UserB ...因此，当UserA当时要求UserB成为朋友时，我们会创建两个 文档，以便UserA可以看到请求的内容，而UserB可以看到待处理的内容 同时我们将这些文档的_id推送到用户的 朋友

3. Now api calls --> Lets say we have two users UserA and UserB... So when UserA requestes UserB to be a friends at that time we make two documents so that UserA can see requested and UserB can see pending and at the same time we push the _id of these documents in user's friends

    const docA = await Friend.findOneAndUpdate(
        { requester: UserA, recipient: UserB },
        { $set: { status: 1 }},
        { upsert: true, new: true }
    )
    const docB = await Friend.findOneAndUpdate(
        { recipient: UserA, requester: UserB },
        { $set: { status: 2 }},
        { upsert: true, new: true }
    )
    const updateUserA = await User.findOneAndUpdate(
        { _id: UserA },
        { $push: { friends: docA._id }}
    )
    const updateUserB = await User.findOneAndUpdate(
        { _id: UserB },
        { $push: { friends: docB._id }}
    )

4..如果UserB接受了请求

4. If UserB acceptes the request

    Friend.findOneAndUpdate(
        { requester: UserA, recipient: UserB },
        { $set: { status: 3 }}
    )
    Friend.findOneAndUpdate(
        { recipient: UserA requester: UserB },
        { $set: { status: 3 }}
    )

5..如果UserB拒绝了请求

5. If UserB rejectes the request

    const docA = await Friend.findOneAndRemove(
        { requester: UserA, recipient: UserB }
    )
    const docB = await Friend.findOneAndRemove(
        { recipient: UserA, requester: UserB }
    )
    const updateUserA = await User.findOneAndUpdate(
        { _id: UserA },
        { $pull: { friends: docA._id }}
    )
    const updateUserB = await User.findOneAndUpdate(
        { _id: UserB },
        { $pull: { friends: docB._id }}
    )

6..获取所有朋友，并检查登录用户是否为该用户的朋友

6. Get all friends and check whether the logged in user is friend of that user or not

User.aggregate([
  { "$lookup": {
    "from": Friend.collection.name,
    "let": { "friends": "$friends" },
    "pipeline": [
      { "$match": {
        "recipient": mongoose.Types.ObjectId("5afaab572c4ec049aeb0bcba"),
        "$expr": { "$in": [ "$_id", "$$friends" ] }
      }},
      { "$project": { "status": 1 } }
    ],
    "as": "friends"
  }},
  { "$addFields": {
    "friendsStatus": {
      "$ifNull": [ { "$min": "$friends.status" }, 0 ]
    }
  }}
])

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