Eventual consistent query read policy
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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 document provides code samples demonstrating how to use a read policy when querying data in Datastore mode across various languages, including C#, Go, Java, Node.js, PHP, Python, and Ruby.\u003c/p\u003e\n"],["\u003cp\u003eThe provided code samples utilize an eventual consistency read option and the \u003ccode\u003ehasAncestor\u003c/code\u003e filter to query for tasks that have an associated ancestor key named "TaskList".\u003c/p\u003e\n"],["\u003cp\u003eTo interact with Datastore mode, you'll need to use the corresponding client libraries for each language, as referenced in the document, and authenticate using Application Default Credentials.\u003c/p\u003e\n"],["\u003cp\u003eEach language section provides links to the respective API reference documentation and instructions for setting up authentication for a local development environment.\u003c/p\u003e\n"],["\u003cp\u003eIt is recommended to use the sample browser to discover code samples for other Google Cloud products.\u003c/p\u003e\n"]]],[],null,["# Eventual consistent query read policy\n\nUse a read policy.\n\nExplore further\n---------------\n\n\nFor detailed documentation that includes this code sample, see the following:\n\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 var results = _db.RunQuery(query,\n ReadOptions.Types.ReadConsistency.Eventual);\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).EventualConsistency()\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 datastore.run(query, ReadOption.eventualConsistency());\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 const query = datastore.createQuery('Task').hasAncestor(ancestorKey);\n\n query.run({consistency: 'eventual'});\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 $query = $datastore-\u003equery()\n -\u003ekind('Task')\n -\u003ehasAncestor($datastore-\u003ekey('TaskList', 'default'));\n $result = $datastore-\u003erunQuery($query, ['readConsistency' =\u003e 'EVENTUAL']);\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 = client.https://cloud.google.com/python/docs/reference/datastore/latest/google.cloud.datastore.client.Client.html#google_cloud_datastore_client_Client_query(kind=\"Task\")\n query.fetch(eventual=True)\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\n tasks = datastore.run query, consistency: :eventual\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)."]]
