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    Class Query (2.21.0) 

      Query 
 ( 
 client 
 , 
 kind 
 = 
 None 
 , 
 project 
 = 
 None 
 , 
 namespace 
 = 
 None 
 , 
 ancestor 
 = 
 None 
 , 
 filters 
 = 
 (), 
 projection 
 = 
 (), 
 order 
 = 
 (), 
 distinct_on 
 = 
 (), 
 explain_options 
 = 
 None 
 , 
 )

    A Query against the Cloud Datastore.

    This class serves as an abstraction for creating a query over data stored in the Cloud Datastore.

    Parameters

    Name
    Description
    client
    Client

    The client used to connect to Datastore.

    kind
    str

    The kind to query.

    project
    str

    (Optional) The project associated with the query. If not passed, uses the client's value.

    namespace
    str

    (Optional) The namespace to which to restrict results. If not passed, uses the client's value.

    ancestor
    Key

    (Optional) key of the ancestor to which this query's results are restricted.

    filters
    tuple[str, str, str]

    Property filters applied by this query. The sequence is (property_name, operator, value) .

    projection
    sequence of string

    fields returned as part of query results.

    order
    sequence of string

    field names used to order query results. Prepend - to a field name to sort it in descending order.

    distinct_on
    sequence of string

    field names used to group query results.

    explain_options
    ExplainOptions

    (Optional) Options to enable query profiling for this query. When set, explain_metrics will be available on the iterator returned by query.fetch().

    Properties

    ancestor

    The ancestor key for the query.

    Returns
    Type
    Description
    Key or None
    The ancestor for the query.

    distinct_on

    Names of fields used to group query results.

    Returns
    Type
    Description
    sequence of string
    The "distinct on" fields set on the query.

    filters

    Filters set on the query.

    Returns
    Type
    Description
    tuple[str, str, str]
    The filters set on the query. The sequence is (property_name, operator, value) .

    kind

    Get the Kind of the Query.

    Returns
    Type
    Description
    str
    The kind for the query.

    namespace

    This query's namespace

    Returns
    Type
    Description
    str or None
    the namespace assigned to this query

    order

    Names of fields used to sort query results.

    Returns
    Type
    Description
    sequence of string
    The order(s) set on the query.

    project

    Get the project for this Query.

    Returns
    Type
    Description
    str
    The project for the query.

    projection

    Fields names returned by the query.

    Returns
    Type
    Description
    sequence of string
    Names of fields in query results.

    Methods

    add_filter

      add_filter 
 ( 
 property_name 
 = 
 None 
 , 
 operator 
 = 
 None 
 , 
 value 
 = 
 None 
 , 
 * 
 , 
 filter 
 = 
 None 
 )

    Filter the query based on a property name, operator and a value.

    Expressions take the form of::

    .add_filter( filter=PropertyFilter('

    where property is a property stored on the entity in the datastore and operator is one of OPERATORS (ie, = , < , <= , > , >= , != , IN , NOT_IN ):

    Both AND and OR operations are supported by passing in a CompositeFilter object to the filter parameter::

    .add_filter( filter=And( [ PropertyFilter('

     ]
   )

    )

    .add_filter( filter=Or( [ PropertyFilter('

    .. testsetup:: query-filter

     import uuid

from google.cloud import datastore 
from google.cloud.datastore.query import PropertyFilter 
client = datastore 
. Client 
()

    .. doctest:: query-filter

     >>> query = client.query(kind='Person')
>>> query = query.add_filter(filter=PropertyFilter('name', '=', 'James'))
>>> query = query.add_filter(filter=PropertyFilter('age', '>', 50))
    Parameters
    Name
    Description
    property_name
    str

    A property name.

    operator
    str

    One of = , < , <= , > , >= , != , IN , NOT_IN .

    value
    int , str , bool , float , NoneType , datetime.datetime , Key

    The value to filter on.

    filter
    CompositeFilter , PropertyFiler

    A instance of a BaseFilter , either a CompositeFilter or PropertyFilter .

    Exceptions
    Type
    Description
    `ValueError
    if operation is not one of the specified values, or if a filter names '__key__' but passes an invalid value (a key is required).
    Returns
    Type
    Description
    Query
    A query object.

    fetch

      fetch 
 ( 
 limit 
 = 
 None 
 , 
 offset 
 = 
 0 
 , 
 start_cursor 
 = 
 None 
 , 
 end_cursor 
 = 
 None 
 , 
 client 
 = 
 None 
 , 
 eventual 
 = 
 False 
 , 
 retry 
 = 
 None 
 , 
 timeout 
 = 
 None 
 , 
 read_time 
 = 
 None 
 , 
 )

    Execute the Query; return an iterator for the matching entities.

    For example:

    .. testsetup:: query-fetch

     import uuid

from google.cloud import datastore 
from google.cloud.datastore.query import PropertyFilter 
unique = str(uuid.uuid4())[0:8]
client = datastore 
. Client 
(namespace='ns{}'.format(unique))

    .. doctest:: query-fetch

     >>> andy = datastore.Entity(client.key('Person', 1234))
>>> andy['name'] = 'Andy'
>>> sally = datastore.Entity(client.key('Person', 2345))
>>> sally['name'] = 'Sally'
>>> bobby = datastore.Entity(client.key('Person', 3456))
>>> bobby['name'] = 'Bobby'
>>> client.put_multi([andy, sally, bobby])
>>> query = client.query(kind='Person')
>>> result = list(query.add_filter(filter=PropertyFilter('name', '=', 'Sally')).fetch())
>>> result
[<Entity('Person', 2345) {'name': 'Sally'}>]

    .. testcleanup:: query-fetch

     client.delete(andy.key)
client.delete(sally.key)
client.delete(bobby.key)
    Parameters
    Name
    Description
    limit
    int

    (Optional) limit passed through to the iterator.

    offset
    int

    (Optional) offset passed through to the iterator.

    start_cursor
    bytes

    (Optional) cursor passed through to the iterator.

    end_cursor
    bytes

    (Optional) cursor passed through to the iterator.

    client
    Client

    (Optional) client used to connect to datastore. If not supplied, uses the query's value.

    eventual
    bool

    (Optional) Defaults to strongly consistent (False). Setting True will use eventual consistency, but cannot be used inside a transaction or with read_time, otherwise will raise ValueError.

    retry
    google.api_core.retry.Retry

    A retry object used to retry requests. If None is specified, requests will be retried using a default configuration.

    timeout
    float

    Time, in seconds, to wait for the request to complete. Note that if retry is specified, the timeout applies to each individual attempt.

    read_time
    datetime

    (Optional) use read_time read consistency, cannot be used inside a transaction or with eventual consistency, or will raise ValueError.

    Returns
    Type
    Description
    Iterator
    The iterator for the query.

    key_filter

      key_filter 
 ( 
 key 
 , 
 operator 
 = 
 "=" 
 )

    Filter on a key.

    Parameters
    Name
    Description
    key
    Key

    The key to filter on.

    operator
    str

    (Optional) One of = , < , <= , > , >= , != , IN , NOT_IN . Defaults to = .

    keys_only

      keys_only 
 ()

    Set the projection to include only keys.
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