node.js - 类型错误 : Cannot use 'in' operator to search for 'pluralization' in undefined

Question

我正在尝试使用鉴别器实现继承，如Mongoose API documentation所示。但是，我不断收到以下错误:

C:\Code\project\node_modules\mongoose\lib\index.js:364 if (!('pluralization' in schema.options)) schema.options.pluralization = thi
^
TypeError: Cannot use 'in' operator to search for 'pluralization' in undefined at Mongoose.model (C:\Code\project\node_modules\mongoose\lib\index.js:364:34)

这是导致上述错误的代码；我尝试扩展 mongoose Schema 类来创建我的基本架构:

var util = require('util');
var mongoose = require('mongoose');
var Schema = mongoose.Schema;

function ResourceSchema() {
  Schema.apply(this, arguments);

  this.add({
    title: String
  });
}
util.inherits(ResourceSchema, Schema);

module.exports = mongoose.model('Resource', ResourceSchema);

我还尝试在最后一行设置集合名称，但这没有帮助。

module.exports = mongoose.model('Resource', ResourceSchema, 'resources');

Answer 1

您正在尝试根据架构类创建模型，而不是架构实例。

改用这个:

module.exports = mongoose.model('Resource', new ResourceSchema());

这类似于您通常创建模型的方式:

var schema = new Schema({ ... }); // or, in your case, ResourceSchema
var model  = mongoose.model('Model', schema);