如何在 couchdb 中索引多维数组

本文介绍了如何在 couchdb 中索引多维数组的处理方法，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

我有一个多维数组，我想用 CouchDB 编制索引(实际上是使用 Cloudant).我的用户拥有他们所属团队的列表.我想搜索以找到该团队的每个成员.所以，给我所有的用户对象，他们有一个 id 为 79d25d41d991890350af672e0b76faed 的团队对象.我试图在Teams.id"上创建一个 json 索引，但没有成功，因为它不是一个直数组，而是一个多维数组.

I have a multidimensional array that I want to index with CouchDB (really using Cloudant). I have users which have a list of the teams that they belong to. I want to search to find every member of that team. So, get me all the User objects that have a team object with id 79d25d41d991890350af672e0b76faed. I tried to make a json index on "Teams.id", but it didn't work because it isn't a straight array but a multidimensional array.

用户

{ "_id": "683be6c086381d3edc8905dc9e948da8", "_rev": "238-963e54ab838935f82f54e834f501dd99", "type": "Feature", "Kind": "Profile", "Email": "gc@gmail", "FirstName": "George", "LastName": "Castanza", "Teams": [ { "id": "79d25d41d991890350af672e0b76faed", "name": "First Team", "level": "123" }, { "id": "e500c1bf691b9cfc99f05634da80b6d1", "name": "Second Team Name", "level": "" }, { "id": "4645e8a4958421f7d843d9b34c4cd9fe", "name": "Third Team Name", "level": "123" } ], "LastTeam": "79d25d41d991890350af672e0b76faed" }

推荐答案

这很像我在 Cloudant 选择器查询 但这是适用于您的问题的交易:

This is a lot like my response at Cloudant Selector Query but here's the deal, applied to your question:

运行此查询的最简单方法是使用Cloudant Query"(或Mango"，在即将发布的 CouchDB 2.0 版本中称为)——而不是 CouchDB 中传统的 MapReduce 视图索引系统.(此博客涵盖了差异:cloudant/blog/mango-json-vs-text-indexes/ 这是一个概述:developer.ibm/clouddataservices/2015/11/24/cloudant-query-json-index-arrays/).

The easiest way to run this query is using "Cloudant Query" (or "Mango", as it's called in the forthcoming CouchDB 2.0 release) -- and not the traditional MapReduce view indexing system in CouchDB. (This blog covers the differences: cloudant/blog/mango-json-vs-text-indexes/ and this one is an overview: developer.ibm/clouddataservices/2015/11/24/cloudant-query-json-index-arrays/).

你的 CQ 索引应该是这样的:

Here's what your CQ index should look like:

{ "index": { "fields": [ {"name": "Teams.[].id", "type": "string"} ] }, "type": "text" }

以及后续查询的样子:

{ "selector": { "Teams": {"$elemMatch": {"id": "79d25d41d991890350af672e0b76faed"}} }, "fields": [ "_id", "FirstName", "LastName" ] }

您可以在 Cloudant 仪表板的查询"部分自己尝试，也可以通过 curl 使用类似以下内容:

You can try it yourself in the "Query" section of the Cloudant dashboard or via curl with something like this:

curl -H "Content-Type: application/json" -X POST -d '{"selector":{"Teams":{"$elemMatch":{"id":"79d25d41d991890350af672e0b76faed"}}},"fields":["_id","FirstName","LastName"]}' broberg.cloudant/teams_test/_find

该数据库是全球可读的，因此您可以在此处查看我在其中创建的示例文档:broberg.cloudant/teams_test/_all_docs?include_docs=true

That database is world-readable, so you can see the sample documents I created in there here: broberg.cloudant/teams_test/_all_docs?include_docs=true

挖掘宋飞主题:D