如何摆脱错误:"OverwriteModelError:编译后无法覆盖未定义的模型"? [英] How to get rid of Error: "OverwriteModelError: Cannot overwrite `undefined` model once compiled."?

问题描述

我有一种通用的方法来更新MongoDB中任何集合的文档吗?

I have a common method for updating document of any collection in MongoDB?

以下代码位于文件名 Deleter.js

module.exports.MongooseDelete = function (schemaObj, ModelObject);
{
  var ModelObj = new mongoose.Model("collectionName",schemaObj);
  ModelObj.remove(ModelObject);
}

并在我的主文件 app.js 中调用如下:

And invoking as follows in my main file app.js:

var ModObj = mongoose.model("schemaName", schemasObj);
var Model_instance = new ModObj();
var deleter = require('Deleter.js');
deleter.MongooseDelete(schemasObj,Model_instance);

我遇到以下错误:

OverwriteModelError: Cannot overwrite `undefined` model once compiled.
    at Mongoose.model (D:\Projects\MyPrjct\node_modules\mongoose\lib\index.js:4:13)

我只能进行第二种方法调用. 请让我知道是否有人可以解决.

I get on 2nd method call only.. Please let me know if any one has got some solution.

推荐答案

我认为您已在同一架构上实例化mongoose.Model()两次.您应该只创建一次每个模型，并且需要一个全局对象来在需要时保留它们

I think you have instantiated mongoose.Model() on the same schema twice. You should have created each model only once and have a global object to get a hold of them when need

我假设您在目录$YOURAPP/models/

$YOURAPPDIR/models/
 - index.js
 - A.js
 - B.js

index.js

module.exports = function(includeFile){
    return require('./'+includeFile);
};

A.js

module.exports = mongoose.model('A', ASchema);

B.js

module.exports = mongoose.model('B', BSchema);

在您的app.js中

APP.models = require('./models');  // a global object

在需要时

// Use A
var A = APP.models('A');
// A.find(.....

// Use B
var B = APP.models('B');
// B.find(.....

这篇关于如何摆脱错误:"OverwriteModelError:编译后无法覆盖未定义的模型"?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！