Query da predecessore
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Query da predecessore.
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Per la documentazione dettagliata che include questo esempio di codice, vedi quanto segue:
Esempio di codice
Salvo quando diversamente specificato, i contenuti di questa pagina sono concessi in base alla licenza Creative Commons Attribution 4.0, mentre gli esempi di codice sono concessi in base alla licenza Apache 2.0. Per ulteriori dettagli, consulta le norme del sito di Google Developers. Java è un marchio registrato di Oracle e/o delle sue consociate.
[[["Facile da capire","easyToUnderstand","thumb-up"],["Il problema è stato risolto","solvedMyProblem","thumb-up"],["Altra","otherUp","thumb-up"]],[["Difficile da capire","hardToUnderstand","thumb-down"],["Informazioni o codice di esempio errati","incorrectInformationOrSampleCode","thumb-down"],["Mancano le informazioni o gli esempi di cui ho bisogno","missingTheInformationSamplesINeed","thumb-down"],["Problema di traduzione","translationIssue","thumb-down"],["Altra","otherDown","thumb-down"]],[],[[["\u003cp\u003eThis page provides code samples for performing ancestor queries in Datastore mode across multiple programming languages, including C#, Go, Java, Node.js, PHP, Python, and Ruby.\u003c/p\u003e\n"],["\u003cp\u003eAncestor queries are used to retrieve entities that are descendants of a specific entity, defined by an ancestor key.\u003c/p\u003e\n"],["\u003cp\u003eEach language example demonstrates how to create an ancestor key and use it in a query to find descendant entities of kind "Task" under a "TaskList" ancestor.\u003c/p\u003e\n"],["\u003cp\u003eThe documentation highlights the importance of setting up Application Default Credentials for authentication and directs users to resources for installing client libraries and accessing API reference documentation.\u003c/p\u003e\n"],["\u003cp\u003eThe page provides a link to the Google Cloud sample browser to further explore other code examples for various products.\u003c/p\u003e\n"]]],[],null,["# Ancestor query.\n\nExplore further\n---------------\n\n\nFor detailed documentation that includes this code sample, see the following:\n\n- [Datastore queries](/datastore/docs/concepts/queries)\n- [Structuring Data for Strong Consistency](/datastore/docs/concepts/structuring_for_strong_consistency)\n\nCode sample\n-----------\n\n### C#\n\n\nTo learn how to install and use the client library for Datastore mode, see\n[Datastore mode client libraries](/datastore/docs/reference/libraries).\n\n\nFor more information, see the\n[Datastore mode C# API\nreference documentation](https://cloud.google.com/dotnet/docs/reference/Google.Cloud.Datastore.V1/latest).\n\n\nTo authenticate to Datastore mode, 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 = new Query(\"Task\")\n {\n Filter = Filter.HasAncestor(_db.CreateKeyFactory(\"TaskList\")\n .CreateKey(keyName))\n };\n\n### Go\n\n\nTo learn how to install and use the client library for Datastore mode, see\n[Datastore mode client libraries](/datastore/docs/reference/libraries).\n\n\nFor more information, see the\n[Datastore mode Go API\nreference documentation](https://cloud.google.com/go/docs/reference/cloud.google.com/go/datastore/latest).\n\n\nTo authenticate to Datastore mode, 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 ancestor := datastore.NameKey(\"TaskList\", \"default\", nil)\n query := datastore.NewQuery(\"Task\").Ancestor(ancestor)\n\n### Java\n\n\nTo learn how to install and use the client library for Datastore mode, see\n[Datastore mode client libraries](/datastore/docs/reference/libraries).\n\n\nFor more information, see the\n[Datastore mode Java API\nreference documentation](https://cloud.google.com/java/docs/reference/google-cloud-datastore/latest/history).\n\n\nTo authenticate to Datastore mode, 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\u003cEntity\u003e query =\n Query.newEntityQueryBuilder()\n .setKind(\"Task\")\n .setFilter(\n PropertyFilter.hasAncestor(\n datastore.newKeyFactory().setKind(\"TaskList\").newKey(\"default\")))\n .build();\n\n### Node.js\n\n\nTo learn how to install and use the client library for Datastore mode, see\n[Datastore mode client libraries](/datastore/docs/reference/libraries).\n\n\nFor more information, see the\n[Datastore mode Node.js API\nreference documentation](https://cloud.google.com/nodejs/docs/reference/datastore/latest).\n\n\nTo authenticate to Datastore mode, 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 ancestorKey = datastore.key(['TaskList', 'default']);\n\n const query = datastore.createQuery('Task').hasAncestor(ancestorKey);\n\n### PHP\n\n\nTo learn how to install and use the client library for Datastore mode, see\n[Datastore mode client libraries](/datastore/docs/reference/libraries).\n\n\nFor more information, see the\n[Datastore mode PHP API\nreference documentation](https://googleapis.github.io/google-cloud-php/#/docs/cloud-datastore/latest).\n\n\nTo authenticate to Datastore mode, 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 $ancestorKey = $datastore-\u003ekey('TaskList', 'default');\n $query = $datastore-\u003equery()\n -\u003ekind('Task')\n -\u003ehasAncestor($ancestorKey);\n\n### Python\n\n\nTo learn how to install and use the client library for Datastore mode, see\n[Datastore mode client libraries](/datastore/docs/reference/libraries).\n\n\nFor more information, see the\n[Datastore mode Python API\nreference documentation](https://cloud.google.com/python/docs/reference/datastore/latest).\n\n\nTo authenticate to Datastore mode, 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 from google.cloud import https://cloud.google.com/python/docs/reference/datastore/latest/\n\n # For help authenticating your client, visit\n # https://cloud.google.com/docs/authentication/getting-started\n client = https://cloud.google.com/python/docs/reference/datastore/latest/.https://cloud.google.com/python/docs/reference/datastore/latest/google.cloud.datastore.client.Client.html()\n\n # Query filters are omitted in this example as any ancestor queries with a\n # non-key filter require a composite index.\n ancestor = client.https://cloud.google.com/python/docs/reference/datastore/latest/google.cloud.datastore.client.Client.html#google_cloud_datastore_client_Client_key(\"TaskList\", \"default\")\n query = client.https://cloud.google.com/python/docs/reference/datastore/latest/google.cloud.datastore.client.Client.html#google_cloud_datastore_client_Client_query(kind=\"Task\", ancestor=ancestor)\n\n### Ruby\n\n\nTo learn how to install and use the client library for Datastore mode, see\n[Datastore mode client libraries](/datastore/docs/reference/libraries).\n\n\nFor more information, see the\n[Datastore mode Ruby API\nreference documentation](/ruby/docs/reference/google-cloud-datastore/latest).\n\n\nTo authenticate to Datastore mode, 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 # task_list_name = \"default\"\n ancestor_key = datastore.key \"TaskList\", task_list_name\n\n query = datastore.query(\"Task\")\n .ancestor(ancestor_key)\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=datastore)."]]