对 Firestore 查询进行无效排序和限制的示例(异步)
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对 Firestore 查询进行无效排序和限制的示例(异步)。
代码示例
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[[["易于理解","easyToUnderstand","thumb-up"],["解决了我的问题","solvedMyProblem","thumb-up"],["其他","otherUp","thumb-up"]],[["很难理解","hardToUnderstand","thumb-down"],["信息或示例代码不正确","incorrectInformationOrSampleCode","thumb-down"],["没有我需要的信息/示例","missingTheInformationSamplesINeed","thumb-down"],["翻译问题","translationIssue","thumb-down"],["其他","otherDown","thumb-down"]],[],[[["\u003cp\u003eThis code example demonstrates an invalid Firestore query that attempts to filter by population and order the results by country.\u003c/p\u003e\n"],["\u003cp\u003eThe provided query will not work because it combines a filter operation with an order operation on different fields, which is not supported by Firestore.\u003c/p\u003e\n"],["\u003cp\u003eAuthentication to Firestore is required and can be set up using Application Default Credentials.\u003c/p\u003e\n"],["\u003cp\u003eThe Google Cloud sample browser contains additional code examples for searching and filtering on various Google Cloud products, including Firestore.\u003c/p\u003e\n"]]],[],null,["# An example of an invalid order and limit Firestore query (async).\n\nCode sample\n-----------\n\n### Python\n\n\nTo authenticate to Firestore, set up Application Default Credentials.\nFor more information, see\n\n[Set up authentication for a local development environment](/docs/authentication/set-up-adc-local-dev-environment).\n\n cities_ref = db.collection(\"cities\")\n query = cities_ref.where(filter=FieldFilter(\"population\", \"\u003e\", 2500000)).order_by(\n \"country\"\n )\n results = query.stream()\n\nWhat's next\n-----------\n\n\nTo search and filter code samples for other Google Cloud products, see the\n[Google Cloud sample browser](/docs/samples?product=firestore)."]]