Cloudant：跨数据库搜索

本文介绍了Cloudant：跨数据库搜索的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我有2个不同数据库的文件：水果，蔬菜。对我来说，使数据库保持分离更容易。

I have documents across 2 different databases: fruits, vegetables. It's easier for me to keep the databases separated.

现在，假设我希望我的用户从这些数据库的任何组合中进行搜索。如果我在三个数据库中运行相同的查询并将结果合并，是否可以工作。也就是说：结果中的 order 字段是否具有绝对值，或者相​​对于其他结果？例如：

Now, suppose I want my user to search from any combination of these databases. Would it work if I run the same query across the three databases, and merge the result. That is: does the order field in a results have an absolute value, or is it relative to the other results? For example:

在水果数据库上运行我的查询：

Run my query on fruits db:

{ total_rows: 2, bookmark: "xxx", rows: [ { id: "Apple", order: [ 2, 220 ], fields: { title: "Apple" } }, { id: "pear", order: [ 1, 4223 ], fields: { title: "Pear" } } }

在蔬菜数据库上运行我的查询：

Run my query on vegetable database:

{ total_rows: 1, bookmark: "xxx", rows: [ { id: "brocolli", order: [ 1.5, 3000 ], fields: { title: "Brocolli" } } }

然后带来结果在一起产生

Then bringing the results together to produce

{ total_rows: 2, bookmark: "xxx", rows: [ { id: "Apple", order: [ 2, 220 ], fields: { title: "Apple" } }, { id: "brocolli", order: [ 1.5, 3000 ], fields: { title: "Brocolli" } }, { id: "pear", order: [ 1, 4223 ], fields: { title: "Pear" } } }

这项工作吗？还是只制作一个 foods 数据库更好？

Would this work? Or is it better to just make a single foods database?

推荐答案

无法使用CouchDB或Cloudant在数据库之间执行联接。您将需要：

It is not possible to perform joins across databases using CouchDB or Cloudant. You will need to either:

• 将所有数据放入单个数据库中，并查询
• 具有独立的数据库，并将每个数据库中的数据复制到单个数据库，并查询
• 具有独立的数据库并在应用程序层中执行联接功能

我已将此问题添加到：如何在Cloudant / CouchDB中使用我的SQL知识？

I've added this question to: How can I use my sql knowledge with Cloudant/CouchDB?