在firestore中有集合cities、posts和users。 posts 包含引用一个 user 和 city 的文档，我想检索所有帖子中的所有数据并编写一个查询:
firestore.collection('posts')
.get()
.then(snapshot => {
snapshot.docs.forEach(post => {
console.log(post.data())
});
});
虽然我的帖子中只有一个文档，但在我的控制台中我得到了数千行数据，我所需要的只是这样:
postId: {
city: "city_name",
user: {
name: "Name",
lastName: "Last"
},
description: "bla bla"
}
如何才能只获取所需的数据而无需所有额外的元数据？ 这是大约 30% 的输出:
<code>
},
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},
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},
},
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"collectionParentIndex": MemoryCollectionParentIndex {
"index": Object {
"species": SortedSet {
"comparator": [Function anonymous],
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"comparator": [Function anonymous],
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"color": false,
"key": ResourcePath {
"len": 0,
"offset": 5,
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"dallol",
"databases",
"(default)",
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"sigir",
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"refsByTarget": SortedSet {
"comparator": [Function anonymous],
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},
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"referenceDelegate": MemoryEagerDelegate {
"inMemoryPins": ReferenceSet {
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"comparator": [Function anonymous],
"data": SortedMap {
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"refsByTarget": SortedSet {
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},
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"comparator": [Function anonymous],
"root": LLRBEmptyNode {
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},
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"comparator": [Function anonymous],
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"databases",
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},
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"onlineStateTracker": OnlineStateTracker {
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"tail": Promise {
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},
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},
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"connection": WebChannelConnection {
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"databaseId": DatabaseId {
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"projectId": "dallol",
},
"forceLongPolling": false,
},
"credentialsProvider": FirebaseCredentialsProvider {
"app": FirebaseAppImpl {
"INTERNAL": Object {
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"getToken": [Function bound ],
"getUid": [Function bound ],
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},
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"factories": Object {
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},
}
</code>最佳答案
使用文档 get()，您无法过滤(减少)其中的字段。使用移动和 Web 客户端 SDK 时，all get() 操作会返回所有匹配文档的 all 字段。如果您需要较少的数据，则必须将数据拆分到不同的文档中并单独查询它们。
关于javascript - 如何从 firestore 获取没有元数据的文档，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/57335738/