NDB Context Usage
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Use Cloud NDB client context to query a Datastore model within a function
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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\u003eCloud NDB client context is used to query a Datastore model within a function.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003endb.Client()\u003c/code\u003e is initiated to create the client used in the context, and \u003ccode\u003endb.Model\u003c/code\u003e can be used to create the model.\u003c/p\u003e\n"],["\u003cp\u003eApplication Default Credentials should be set up to authenticate to Datastore mode.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003eBook.query()\u003c/code\u003e is called within the context to execute the query.\u003c/p\u003e\n"]]],[],null,["# NDB Context Usage\n\nUse Cloud NDB client context to query a Datastore model within a function\n\nExplore further\n---------------\n\n\nFor detailed documentation that includes this code sample, see the following:\n\n- [Migrate to Cloud NDB](/appengine/migration-center/standard/python/migrate-to-cloud-ndb)\n\nCode sample\n-----------\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 ndb\n\n\n class Book(ndb.Model):\n title = ndb.StringProperty()\n\n\n client = ndb.Client()\n\n\n def list_books():\n with client.context():\n books = Book.query()\n for book in books:\n print(book.to_dict())\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)."]]
