E11000重复键错误收集

Question

const UserSchema = new Schema ({
  mobile: {type: String, unique: true, required: [true, 'Mobile Required']},
  verified: {type: Boolean, default: false},
  password: {type: String, required: [true, 'Password Required']},
  salt: {type: String, required: [true, 'Salt Required']},
  type: {type: Number, required: [true, 'User Type Required']},
  storeId: {type: Schema.Types.ObjectId, ref: 'Store', default: null},
  username: {type: String, lowercase: true, unique: true},
  userInfo: {
    name: String,
    email: String,
    address: String,
    postcode: String,
  },
  likes: [{type: Schema.Types.ObjectId, ref: 'Post'}],
}, {
  timestamps: true,
  versionKey: false,
});

这是数据模式，在第一次插入后，第二次总是输出错误。电子邮件字段未编入索引，并且第一个电子邮件字段的电子邮件字段不为空。第二个插入也不为空。

E11000 duplicate key error collection: gdaymobile.users index: email_1 dup key: { : null }