你如何从猫鼬中删除模型？

I don't mean remove a document or documents. I mean remove the model entirely so that mongoose is no longer aware of it. After declaring a model I can't figure out how to make mongoose forget that model so that it could be recreated.

我不是指删除文件或文件。我的意思是完全删除模型，以便猫鼬不再意识到它。在声明一个模型之后，我无法弄清楚如何让mongoose忘记该模型以便可以重新创建它。

mongoose.model('Book', bookSchema);
mongoose.model('Book', bookSchema);

Currently the above throws an exception.

目前上面抛出一个例外。

OverwriteModelError: Cannot overwrite 'Book' model once compiled.

OverwriteModelError：编译后无法覆盖'Book'模型。

I'd like to be able do something like this...

我希望能做到这样的事......

mongoose.model('Book', bookSchema);
mongoose.removeModel('Book');
mongoose.model('Book', bookSchema);

...and not get any errors. Any ideas?

......而且没有任何错误。有任何想法吗？

2 个解决方案

#1

try this

尝试这个

delete mongoose.connection.models['Book'];

and then re-register/re-initialize it . it will work fine

然后重新注册/重新初始化它。它会工作正常

#2

It appears that you'd have to overwrite some of the source code in order to be able to remove a model an add a new one since Mongoose makes sure that a model doesn't exist before it's willing to create a new one, which may or may not be more than you care to do:

看来你必须覆盖一些源代码，以便能够删除模型并添加新的模型，因为Mongoose确保模型在它愿意创建新模型之前不存在，这可能是或者可能不是你想做的事：

if (this.models[name] && !collection) {
    // model exists but we are not subclassing with custom collection
    if (schema instanceof Schema && schema != this.models[name].schema) {
      throw new MongooseError.OverwriteModelError(name);
    }
    return this.models[name];
}

Line 587 https://github.com/LearnBoost/mongoose/blob/master/lib/connection.js

第587行https://github.com/LearnBoost/mongoose/blob/master/lib/connection.js

Question Author's Update:

Thanks to this answer I discovered that you can access the models defined on the connection through connection.models. In my scenario I was testing a mongoose plugin with Mocha and and I wanted to clear the models between each unit test.

由于这个答案，我发现您可以通过connection.models访问连接上定义的模型。在我的场景中，我正在使用Mocha测试mongoose插件，并且我想在每个单元测试之间清除模型。

afterEach(function () {
    mongoose.connection.models = {};
});