Query a collection group using a partitioned query
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Query a collection group using a partitioned query
Code sample
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[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],[],[[["\u003cp\u003eThis content demonstrates how to query a collection group in Firestore using a partitioned query.\u003c/p\u003e\n"],["\u003cp\u003eThe provided Go code sample shows how to authenticate to Firestore using Application Default Credentials.\u003c/p\u003e\n"],["\u003cp\u003eThe code retrieves partitioned queries from a specified collection group, with a defined maximum partition count.\u003c/p\u003e\n"],["\u003cp\u003eThe example code iterates over the documents from one of the partitioned queries, demonstrating how to handle each document within a partition.\u003c/p\u003e\n"]]],[],null,["# Query a collection group using a partitioned query\n\nCode sample\n-----------\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 cities := client.CollectionGroup(\"cities\")\n\n // Get a partioned query for the cities collection group, with a maximum\n // partition count of 10\n partitionedQueries, err := cities.GetPartitionedQueries(ctx, 10)\n if err != nil {\n \treturn fmt.Errorf(\"GetPartitionedQueries: %w\", err)\n }\n\n fmt.Printf(\"Collection Group query partitioned to %d queries\\n\", len(partitionedQueries))\n\n // Retrieve the first query and iterate over the documents contained.\n query := partitionedQueries[0]\n iter := query.Documents(ctx)\n for {\n \tdoc, err := iter.Next()\n \tif err == iterator.Done {\n \t\tbreak\n \t}\n \tif err != nil {\n \t\treturn fmt.Errorf(\"documents iterator: %w\", err)\n \t}\n \tfmt.Println(doc.Data())\n }\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)."]]