如何在 mongodb 中自动删除对象 ID 引用

Posted 2023-03-11

【中文标题】如何在 mongodb 中自动删除对象 ID 引用

【英文标题】：How to auto delete ObjectId referances in mongodb

【发布时间】：2021-02-19 04:17:10

【问题描述】：

当通知被删除时，我试图自动删除来自用户的通知引用

userSchema 看起来像

const mongoose = require("mongoose");

const userSchema = new mongoose.Schema(
 
  notifications: [
    
      type: mongoose.Schema.Types.ObjectId,
      ref: "Notification",
    ,
  ],
);

module.exports = mongoose.model("User", userSchema);

通知模型如下所示

    const mongoose = require("mongoose");

const notificationSchema = new mongoose.Schema(
  type: String,
  created: 
    type: Date,
    default: Date.now,
  ,
);
notificationSchema.pre("deleteOne", function (next) 
  this.model("User").deleteOne( notifications: this._id , next);
);
module.exports = mongoose.model("Notification", notificationSchema);

当我尝试删除通知时，我收到一个错误，看起来像

ObjectParameterError: Parameter "obj" to Document() must be an object, got User

还有一种方法可以使用 TTL 通知自动删除它[用户中通知的引用]​​

【参考方案1】：

好的，经过几次尝试和错误。我想出了这个解决方案..

    const mongoose = require("mongoose");
const notificationSchema = new mongoose.Schema(
  type: String,
  created: 
    type: Date,
    default: Date.now,
  ,
);
notificationSchema.pre("deleteOne", function (next) 
  let id = this.getQuery()["_id"];
  mongoose.model("User").findOne(
    
      notifications: id,
    ,
    (err, res) => 
      const index = res.notifications.findIndex((x) => x._id == id);
      res.notifications.splice(index, 1);
      res.save();
      next();
    
  );
);
module.exports = mongoose.model("Notification", notificationSchema);

我可以做些改进吗？