Firestore综合索引排序不修改顺序 [英] Firestore Composite Index Sort Not Modifying Order

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本文介绍了Firestore综合索引排序不修改顺序的处理方法，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

使用Firestore多属性复合索引排序，返回的数据顺序不变.将其与对一个属性执行的原始排序进行比较.当前，返回的数据仅按时间戳排序，并没有应用复合索引.

The order of the data returned is not changing using a Firestore multiple attribute composite index sort. This is compared to the original sort performed on one attribute. Currently, the data is returned being only sorted by timestamp with and without the composite index applied.

使用时间戳和 qualityScore 的复合索引时，数据应按照 qualityScore 属性进行排序.

The data should sort in terms of the qualityScore attribute when using the composite index of the timestamp and qualityScore.

查询结果由 FirestorePagingOptions.Builder< Content>()方法 setQuery()使用.

val options: FirestorePagingOptions<Content> = FirestorePagingOptions.Builder<Content>()
            .setLifecycleOwner(this)
            .setQuery(viewModel.contentFeedQuery, config, Content::class.java).build()

我正在从 FirestorePagingAdapter 的 onBindViewHolder 中读取结果.

I'm reading the results from the onBindViewHolder of the FirestorePagingAdapter.

override fun onBindViewHolder(viewHolder: ViewHolder, position: Int, content: Content) {
            println("QUALITY_SCORE: " + content.timestamp + " " + content.qualityScore)
            viewHolder.bind(content)
        }

原始排序

return FirestoreCollections.contentCollection
.collection(ALL_COLLECTION)
.orderBy(TIMESTAMP, DESCENDING)
.whereGreaterThanOrEqualTo(TIMESTAMP,getTimeframe(WEEK))

结果

2018-08-26 01:15:08.548 27668-27668/app.carpecoin I/System.out: QUALITY_SCORE: Fri Aug 24 15:17:26 PDT 2018 17.0
2018-08-26 01:15:08.574 27668-27668/app.carpecoin I/System.out: QUALITY_SCORE: Fri Aug 24 13:30:44 PDT 2018 17.0
2018-08-26 01:15:11.698 27668-27668/app.carpecoin I/System.out: QUALITY_SCORE: Fri Aug 24 11:16:47 PDT 2018 16.0
2018-08-26 01:15:11.728 27668-27668/app.carpecoin I/System.out: QUALITY_SCORE: Fri Aug 24 08:09:52 PDT 2018 18.0
2018-08-26 01:15:11.777 27668-27668/app.carpecoin I/System.out: QUALITY_SCORE: Fri Aug 24 07:38:36 PDT 2018 21.0
2018-08-26 01:15:11.804 27668-27668/app.carpecoin I/System.out: QUALITY_SCORE: Fri Aug 24 06:16:23 PDT 2018 20.0
2018-08-26 01:15:11.849 27668-27668/app.carpecoin I/System.out: QUALITY_SCORE: Thu Aug 23 15:39:59 PDT 2018 15.0
2018-08-26 01:15:11.890 27668-27668/app.carpecoin I/System.out: QUALITY_SCORE: Thu Aug 23 07:23:51 PDT 2018 1.0
2018-08-26 01:15:11.915 27668-27668/app.carpecoin I/System.out: QUALITY_SCORE: Wed Aug 22 16:15:02 PDT 2018 5.0
2018-08-26 01:15:11.947 27668-27668/app.carpecoin I/System.out: QUALITY_SCORE: Wed Aug 22 08:00:12 PDT 2018 22.0
2018-08-26 01:15:12.000 27668-27668/app.carpecoin I/System.out: QUALITY_SCORE: Tue Aug 21 17:28:03 PDT 2018 19.0
2018-08-26 01:15:12.050 27668-27668/app.carpecoin I/System.out: QUALITY_SCORE: Tue Aug 21 08:59:06 PDT 2018 6.0
2018-08-26 01:15:12.115 27668-27668/app.carpecoin I/System.out: QUALITY_SCORE: Tue Aug 21 08:17:53 PDT 2018 7.0
2018-08-26 01:15:12.167 27668-27668/app.carpecoin I/System.out: QUALITY_SCORE: Mon Aug 20 22:40:56 PDT 2018 9.0
2018-08-26 01:15:12.235 27668-27668/app.carpecoin I/System.out: QUALITY_SCORE: Mon Aug 20 06:58:18 PDT 2018 10.0
2018-08-26 01:15:12.318 27668-27668/app.carpecoin I/System.out: QUALITY_SCORE: Mon Aug 20 04:07:27 PDT 2018 12.0
2018-08-26 01:15:12.367 27668-27668/app.carpecoin I/System.out: QUALITY_SCORE: Sun Aug 19 21:08:31 PDT 2018 8.0
2018-08-26 01:15:12.410 27668-27668/app.carpecoin I/System.out: QUALITY_SCORE: Sun Aug 19 15:11:37 PDT 2018 14.0
2018-08-26 01:15:12.449 27668-27668/app.carpecoin I/System.out: QUALITY_SCORE: Sun Aug 19 03:35:52 PDT 2018 200.0

综合索引排序

return FirestoreCollections.contentCollection
.collection(ALL_COLLECTION)
.orderBy(TIMESTAMP, DESCENDING)
.orderBy(QUALITY_SCORE, DESCENDING)
.whereGreaterThanOrEqualTo(TIMESTAMP,getTimeframe(WEEK))

结果

2018-08-26 01:13:54.549 26943-26943/app.carpecoin I/System.out: QUALITY_SCORE: Fri Aug 24 15:17:26 PDT 2018 17.0
2018-08-26 01:13:54.579 26943-26943/app.carpecoin I/System.out: QUALITY_SCORE: Fri Aug 24 13:30:44 PDT 2018 17.0
2018-08-26 01:13:58.110 26943-26943/app.carpecoin I/System.out: QUALITY_SCORE: Fri Aug 24 11:16:47 PDT 2018 16.0
2018-08-26 01:13:58.205 26943-26943/app.carpecoin I/System.out: QUALITY_SCORE: Fri Aug 24 08:09:52 PDT 2018 18.0
2018-08-26 01:13:58.339 26943-26943/app.carpecoin I/System.out: QUALITY_SCORE: Fri Aug 24 07:38:36 PDT 2018 21.0
2018-08-26 01:13:58.420 26943-26943/app.carpecoin I/System.out: QUALITY_SCORE: Fri Aug 24 06:16:23 PDT 2018 20.0
2018-08-26 01:13:58.590 26943-26943/app.carpecoin I/System.out: QUALITY_SCORE: Thu Aug 23 15:39:59 PDT 2018 15.0
2018-08-26 01:13:58.840 26943-26943/app.carpecoin I/System.out: QUALITY_SCORE: Thu Aug 23 07:23:51 PDT 2018 1.0
2018-08-26 01:13:58.940 26943-26943/app.carpecoin I/System.out: QUALITY_SCORE: Wed Aug 22 16:15:02 PDT 2018 5.0
2018-08-26 01:13:59.041 26943-26943/app.carpecoin I/System.out: QUALITY_SCORE: Wed Aug 22 08:00:12 PDT 2018 22.0
2018-08-26 01:13:59.183 26943-26943/app.carpecoin I/System.out: QUALITY_SCORE: Tue Aug 21 17:28:03 PDT 2018 19.0
2018-08-26 01:13:59.360 26943-26943/app.carpecoin I/System.out: QUALITY_SCORE: Tue Aug 21 08:59:06 PDT 2018 6.0
2018-08-26 01:13:59.427 26943-26943/app.carpecoin I/System.out: QUALITY_SCORE: Tue Aug 21 08:17:53 PDT 2018 7.0
2018-08-26 01:13:59.467 26943-26943/app.carpecoin I/System.out: QUALITY_SCORE: Mon Aug 20 22:40:56 PDT 2018 9.0
2018-08-26 01:13:59.517 26943-26943/app.carpecoin I/System.out: QUALITY_SCORE: Mon Aug 20 06:58:18 PDT 2018 10.0
2018-08-26 01:13:59.567 26943-26943/app.carpecoin I/System.out: QUALITY_SCORE: Mon Aug 20 04:07:27 PDT 2018 12.0
2018-08-26 01:13:59.633 26943-26943/app.carpecoin I/System.out: QUALITY_SCORE: Sun Aug 19 21:08:31 PDT 2018 8.0
2018-08-26 01:13:59.703 26943-26943/app.carpecoin I/System.out: QUALITY_SCORE: Sun Aug 19 15:11:37 PDT 2018 14.0
2018-08-26 01:13:59.769 26943-26943/app.carpecoin I/System.out: QUALITY_SCORE: Sun Aug 19 03:35:52 PDT 2018 200.0

综合索引设置

我在测试各种组合时设置了2个复合索引，以便获得在特定的时间戳之后按 qualityScore 排序返回的数据的结果.

Composite Index Setup

I setup 2 composite indexes as I was testing various combinations in order to achieve a result of the data being returned sorted by qualityScore after a specific timestamp.

推荐答案

您调用 .orderBy(TIMESTAMP，DESCENDING).orderBy(QUALITY_SCORE，DESCENDING).这意味着文档首先按时间戳记降序排列，而当文档相同时，它们按质量分数降序排列.

You call .orderBy(TIMESTAMP, DESCENDING).orderBy(QUALITY_SCORE, DESCENDING). This means that the documents are first ordered by descending timestamp, and when those are the same, they are ordered by descending quality score.

由于结果集中的所有文档都有唯一的时间戳，因此这是唯一可见的结果.只有当多个文档的第一个排序字段的值相同时，第二个排序字段才有意义.

Since all documents in the result set have a unique timestamp, that is the only visible result. Only when multiple documents have the same value for the first sort field, does the second sort field become relevant.

这篇关于Firestore综合索引排序不修改顺序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IT屋！

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