Como classificar e limitar consultas do Firestore em ordem decrescente
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Como classificar e limitar consultas do Firestore em ordem decrescente
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[[["Fácil de entender","easyToUnderstand","thumb-up"],["Meu problema foi resolvido","solvedMyProblem","thumb-up"],["Outro","otherUp","thumb-up"]],[["Difícil de entender","hardToUnderstand","thumb-down"],["Informações incorretas ou exemplo de código","incorrectInformationOrSampleCode","thumb-down"],["Não contém as informações/amostras de que eu preciso","missingTheInformationSamplesINeed","thumb-down"],["Problema na tradução","translationIssue","thumb-down"],["Outro","otherDown","thumb-down"]],[],[[["\u003cp\u003eThis page demonstrates how to order and limit Firestore query results in descending order.\u003c/p\u003e\n"],["\u003cp\u003eCode samples are provided in C#, Go, Java, Node.js, PHP, Python, and Ruby, showcasing how to apply ordering and limiting to a Firestore query.\u003c/p\u003e\n"],["\u003cp\u003eEach code example sets up authentication using Application Default Credentials, as required to access Firestore.\u003c/p\u003e\n"],["\u003cp\u003eThe provided examples use \u003ccode\u003e.orderByDescending()\u003c/code\u003e or the equivalent, then \u003ccode\u003e.limit(3)\u003c/code\u003e to return only the top three results when ordering data in descending order.\u003c/p\u003e\n"],["\u003cp\u003eThe information contained on this page is also covered in the 'Order and limit data' documentation.\u003c/p\u003e\n"]]],[],null,["# Ordering and limiting Firestore queries in descending order\n\nExplore further\n---------------\n\n\nFor detailed documentation that includes this code sample, see the following:\n\n- [Order and limit data](/firestore/native/docs/query-data/order-limit-data)\n- [Order and limit data with Cloud Firestore](https://firebase.google.com/docs/firestore/query-data/order-limit-data)\n\nCode sample\n-----------\n\n### C#\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 Query query = citiesRef.OrderByDescending(\"Name\").Limit(3);\n\n### Go\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 query := cities.OrderBy(\"name\", firestore.Desc).Limit(3)\n\n### Java\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 Query query = cities.orderBy(\"name\", Direction.DESCENDING).limit(3);\n\n### Node.js\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 const lastThreeRes = await citiesRef.orderBy('name', 'desc').limit(3).get();\n\n### PHP\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 $query = $citiesRef-\u003eorderBy('name', 'DESC')-\u003elimit(3);\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.order_by(\"name\", direction=firestore.Query.DESCENDING).limit(3)\n results = query.stream()\n\n### Ruby\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 query = cities_ref.order(\"name\", \"desc\").limit(3)\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)."]]
