如何在流星应用程序中为mongodb添加两列唯一ID？ [英] How can I add a two column unique id to the mongodb in a meteor app?

问题描述

我正在尝试在流星应用程序中的基础mongodb上创建一个两列唯一索引并遇到麻烦。我在流星文档中找不到任何内容。我试过Chrome控制台。我从学期开始尝试，甚至试图将mongod指向/ db / dir里面的.meteor。我试过了

I am trying to create a two column unique index on the underlying mongodb in a meteor app and having trouble. I can't find anything in the meteor docs. I have tried from the chrome console. I have tried from term and even tried to point mongod at the /db/ dir inside .meteor . I have tried

Collection.ensureIndex（{first_id：1，another_id：1}，{unique：true}）; 变种。

我希望能够防止meteor app mongo集合上的重复条目。

I want to be able to prevent duplicate entries on a meteor app mongo collection.

想知道是否有人想出这个？

Wondering if anyone has figured this out?

我回答了我自己的问题，这是一个菜鸟。

I answered my own question, what a noob.

我想出来。

1. 启动流星服务器

1. Start meteor server

打开第二终端键入 meteor mongo

然后创建索引...例如，我为thumbsup和thumbsdown类型系统的记录做了这些。

Then create your index...for example I did these for records of thumbsup and thumbsdown type system.

db.thumbsup.ensureIndex({item_id: 1, user_id: 1}, {unique: true})
db.thumbsdown.ensureIndex({item_id: 1, user_id: 1}, {unique: true})

现在，只需要弄清楚一个bootstrap安装设置，当你推送到prod而不是手动时，会创建这些设置。

Now, just gotta figure out a bootstrap install setup that creates these when pushed to prod instead of manually.

推荐答案

根据文档Minimongo目前没有索引。很快就会到来。并且查看Collection上可用的方法，没有 ensureIndex 。

According to the docs "Minimongo currently doesn't have indexes. This will come soon." And looking at the methods available on a Collection, there's no ensureIndex.

您可以运行 meteor mongo 对于mongo shell并启用索引服务器端，但Collection对象仍然不知道它们。因此，应用程序将允许您向Collection缓存添加多个实例，而在服务器端，其他插入将无提示失败（错误将写入输出）。当您进行硬页面刷新时，应用程序将与服务器重新同步

You can run meteor mongo for a mongo shell and enable the indexes server-side, but the Collection object still won't know about them. So the app will let you add multiple instances to the Collection cache, while on the server-side the additional inserts will fail silently (errors get written to the output). When you do a hard page refresh, the app will re-sync with server

因此，您现在最好的选择可能是：

So your best bet for now is probably to do something like:

var count = MyCollection.find({first_id: 'foo', another_id: 'bar'}).count()
if (count === 0)
    MyCollection.insert({first_id: 'foo', another_id: 'bar'});

这显然不理想，但工作正常。您还可以在服务器上的mongodb中启用索引，因此即使在竞争条件下您也不会实际获得重复记录。

Which is obviously not ideal, but works ok. You could also enable indexing in mongodb on the server, so even in the case of a race condition you won't actually get duplicate records.

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