Key filter
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For detailed documentation that includes this code sample, see the following:
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 page demonstrates how to use a key filter within Datastore queries across multiple programming languages.\u003c/p\u003e\n"],["\u003cp\u003eCode samples are provided in C#, Go, Java, Node.js, PHP, Python, and Ruby, each demonstrating a query that filters based on the \u003ccode\u003e__key__\u003c/code\u003e property.\u003c/p\u003e\n"],["\u003cp\u003eThe examples use the \u003ccode\u003e__key__\u003c/code\u003e to filter for entities greater than a specific key value.\u003c/p\u003e\n"],["\u003cp\u003eEach language section includes links to documentation on how to install the client library, as well as links to the relevant API reference.\u003c/p\u003e\n"],["\u003cp\u003eThe guide instructs on setting up Application Default Credentials for authentication and gives a link to further information on that process.\u003c/p\u003e\n"]]],[],null,["# Key filter\n\nUse a key filter.\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\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.GreaterThan(\"__key__\", _keyFactory.CreateKey(\"aTask\"))\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 key := datastore.NameKey(\"Task\", \"someTask\", nil)\n query := datastore.NewQuery(\"Task\").FilterField(\"__key__\", \"\u003e\", key)\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(PropertyFilter.gt(\"__key__\", keyFactory.newKey(\"someTask\")))\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 query = datastore\n .createQuery('Task')\n .filter(\n new PropertyFilter('__key__', '\u003e', datastore.key(['Task', 'someTask'])),\n );\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 -\u003efilter('__key__', '\u003e', $datastore-\u003ekey('Task', 'someTask'));\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 first_key = client.https://cloud.google.com/python/docs/reference/datastore/latest/google.cloud.datastore.client.Client.html#google_cloud_datastore_client_Client_key(\"Task\", \"first_task\")\n # key_filter(key, op) translates to add_filter('__key__', op, key).\n query.https://cloud.google.com/python/docs/reference/datastore/latest/google.cloud.datastore.query.Query.html#google_cloud_datastore_query_Query_key_filter(first_key, \"\u003e\")\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 query = datastore.query(\"Task\")\n .where(\"__key__\", \"\u003e\", datastore.key(\"Task\", \"someTask\"))\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)."]]