问题描述
我正在尝试学习如何开发Foxx服务.
I'm trying to learn how to develop Foxx services.
人们使用许多示例:
const someCollection = module.context.collection('someCollectionName');
但是在我的项目中，此代码不起作用.someCollection始终为null，但它存在于集合中.
But in my project this code doesn't work.someCollection always null, but it's exist in collections.
此代码可完美运行:
const db = require('@arangodb').db;
const someCollection = db._collection('someCollectionName');
我的问题是为什么第一个代码不起作用?
My question is why first code isn't work?
推荐答案
Foxx服务旨在具有自己的集合，并且可以多次安装.
Foxx services are intended to have their own collections, and being able to be installeable multiple times.
因此，module.context.collection('someCollectionName');将为您提供一个以Foxx-Service的安装点为前缀的集合，其中db._collection('someCollectionName');始终会为您提供与该foxx服务的安装相同的集合名称，因此可能需要进行多次安装互相干扰.
Thus module.context.collection('someCollectionName'); will give you a collection prefixed with the mountpoint of your Foxx-Service, wheres db._collection('someCollectionName'); will always give you the same collection name regardles of which installation of this foxx services you are in - thus several installations may interfere each other.
一个完整的示例(包含集合和简单的代码存根进行操作)最简单的入门方法是在用户界面中选择以下点击路径:
The easiest way to get started with a complete example that has collections and simple code stubs for manipulation is to choose this clickpath in the UI:
Services-> Add Service => New
然后填充
'someCollectionName'转换为Document Collections:
这篇关于为什么在ArangoDB中module.context.collection返回null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！