这类问题已经问过很多次了，我试过了每一个答案。在大多数情况下，答案类似于删除mongo自动创建的用户索引。我做了太多次了。但每次我在服务器上发出请求时，它都会被再次创建（索引）。当我写作时 db.compnies.getIndexes() 1.我明白了

[
        {
                "v" : 2,
                "key" : {
                        "_id" : 1
                },
                "name" : "_id_"
        },
        {
                "v" : 2,
                "unique" : true,
                "key" : {
                        "username" : 1
                },
                "name" : "username_1",
                "background" : true
        }
]

被删除后 db.compnies.dropIndexes({"username":1}) 1.我明白了 [ { "v" : 2, "key" : { "_id" : 1 }, "name" : "_id_" } ] 作为一个 db.compnies.getIndexes() .
在每一个新的请求之后，上述过程都会重复。我在过去两天就面临这个错误。我无法提交我的数据。请帮帮我。非常感谢。
以下是我的用户模型：

const mongoose = require("mongoose");
const passportLocalMongoose = require("passport-local-mongoose");
// const findOrCreate = require('mongoose-findorcreate');

const logoSchema=new mongoose.Schema({
    url:String,
    filename:String
});
const UserSchema = new mongoose.Schema({
    email: {
        type: String,
    },
       username:{
        type:String,
        unique:false
     },
    // password:{
    //     type:String,
    // },
 googleId : {
        type : String, 
    } , 
 name : {
     type : String,
    } ,
 firstName : {
     type : String,
 } ,
 lastName : {
     type : String,
 },
 age:{
     type:String
 },
 compny:{
     type:String
 },
//   logo :[logoSchema],

logo: {
    type: String,
    required: [true, "Uploaded file must have a name"],
  },

 createdAt:{
   type: Date,
   default : Date.now
 }    
});
UserSchema.plugin(passportLocalMongoose);
//  UserSchema.plugin(findOrCreate);

const User = mongoose.model('User', UserSchema);
module.exports = User;

这是我的公司模型：

const mongoose=require("mongoose");
const passportLocalMongoose = require("passport-local-mongoose");

// const ImageSchema = new mongoose.Schema({
//     url: String,
//     filename: String
// });

const compnySchema= new mongoose.Schema({
    name:{
        type:String,
        // required:true
    },
    location:{
        type:String,
        // required:true
    },
    category:{
        type:String,
        // required:true
    },
    about:{
        type:String
    },
      logo: {
        type: String,
        required: [true, "Uploaded file must have a name"],
      },
      count:{
          type:Number
      }
});
compnySchema.plugin(passportLocalMongoose);
const Compny= mongoose.model("Compny", compnySchema);
module.exports=Compny;