Firestore - 嵌套查询 [英] Firestore - Nested query

问题描述

我对 firebase 真的很陌生，老实说，我发现查询很难写.我正在使用 firebase_admin 在 python 中编写脚本，我希望查询/答案使用 python 代码，但使用任何其他编程语言都可以.

I'm really new to firebase and to be honest I find queries hard to write. I'm working on a script in python using firebase_admin and i'd like the query/answer to be in python code, but in any other programming language is fine.

这是我的一个文档，一个文档包含photos set

Here's my one of my document, one document contains photos set

photos: {
    id1: true
    id2: true
}

我想成为 ale 来检索照片对象中具有 id1 的所有项目，对此的查询是什么?

I want to be ale to retrieve all items where they have id1 in photos object, what would be the query for that?

推荐答案

作为 有关简单查询的 Firebase 文档 显示:

# Create a reference to the photos collection
ref = db.collection('documents')

# Create a query against the collection
query_ref = ref.where(u'photos.id1', u'==', True)

对于 . 表示法，请参阅关于 嵌套对象中的字段.

For the . notation, see the documentation on fields in nested objects.

请注意，您可能希望更改数据模型以使用该数据的数组，如 数组现在可用于建模数学集.在您的文档中使用这样的数组:

Note that you'll probably want to change your data model to use an array for this data, as arrays can now be used to model mathematical sets. With a an array like this in your document:

user: ['id1', 'id2']

然后你可以过滤:

photos_ref = db.collection('documents')

query = photos_ref.where(u'photos', u'array_contains', u'id1')

要向此数组添加/删除项目-that-behaves-like-a-set，请参阅 更新数组中的元素.

To add/remove items to this array-that-behaves-like-a-set, see the documentation on updating elements in an array.

这篇关于Firestore - 嵌套查询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！