使用Rails 4（和Hstore）在PostgreSQL中存储嵌套哈希 [英] Storing nested Hashes in PostgreSQL with Rails 4 (and Hstore)

问题描述

我有一个Rails应用程序，该应用程序聚集了Google API的许多数据。我目前将JSON响应存储在MongoDB中（因此我的Rails应用同时具有pg和mongo）。但是，今天，我遇到了PostgreSQL Hstore扩展，因此决定尝试一下。

I have a Rails app that aggregates a lot of data from Google API's. I store the JSON responses in MongoDB currently (so my Rails app has both pg and mongo). However, today, I've came across PostgreSQL Hstore extension, and I've decided to give it a try.

不幸的是，我遇到了一个问题。 API提供的JSON具有多个层次，因此 JSON.parse 之后的Ruby Hash包含哈希，其中包含新的哈希。但是， Hstore 是字符串键/值存储，并且深度仅为1级。因此，第一个哈希中的哈希只是变成字符串。

Unfortunately, I've ran into a problem. JSON given by API's is multiple levels deep, so Ruby Hash after JSON.parse contains hashes, which contain new hashes. However, Hstore is string key/value store, and it only goes 1 level deep. So hashes within first hash just become strings.

我发现要做的真正讨厌的黑客是 eval 变成字符串：

The really nasty hack I found to do is to eval the hashes that were turned into strings:

eval("{ "foo" => "bar" }")

我不喜欢这样。关于该怎么做的任何提示？我应该继续使用MongoDB，还是有更好的方法在PG中存储多级深哈希？

I do not like this. Any tips on what to do? Should I keep using MongoDB or is there any better way to store multi-level deep hashes in PG?

推荐答案

嵌套Hstore 是一种支持hstore中嵌套哈希（以及数组和其他类型）的gem，其实现的功能类似于文档像MongoDB这样的存储。它使用了hstore和JSON序列化的混合体。不过尚未在Rails 4上进行过测试。

Nested Hstore is a gem that supports nested hashes (and arrays and other types) in hstores, achieving something similar to a document store like MongoDB. It uses a hybrid of hstore and JSON serialization. It hasn't been tested on Rails 4, though.

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