pyravendb

Overview

PyRavenDB is a python client api for RavenDB, a NoSQL document database. The API can handle most CRUD scenarios, including full support for replication, failover, dynamic queries, etc.

.. code-block:: python

with document_store.DocumentStore(urls=["http://localhost:8080"], database="PyRavenDB") as store:
    store.initialize()
    with store.open_session() as session:
    foo = session.load("foos/1")

Installation

There are three ways to install pyravendb.

• Install from PyPi <https://pypi.python.org/pypi>, as pyravendb <https://pypi.python.org/pypi/pyravendb>. .. code-block:: bash

   pip install pyravendb
  

• Install from source, via PyPi. From pyravendb, download, open the source (pyravendb-x.x.x.zip) and run setup.py. .. code-block:: bash

     python setup.py install
  

• Install from source via GitHub <https://github.com/ravendb/RavenDB-Python-Client>_.

  .. code-block:: bash

     git clone https://github.com/IdanHaim/RavenDB-Python-Client.git
     cd RavenDB-Python-Client
     git fetch <remote_name> v4.0
     git checkout v4.0
     git pull <remote_name> v4.0
     python setup.py install
  

Usage

Load a single or several document\s from the store:

.. code-block:: python

from pyravendb.store import document_store

store =  document_store.DocumentStore(urls=["http://localhost:8080"], database="PyRavenDB")
store.initialize()
with store.open_session() as session:
    foo = session.load("foos/1")

load method have the option to track entity for you the only thing you need to do is add object_type when you call to load (load method will return a dynamic_structure object by default) for class with nested object you can call load with nested_object_types dictionary for the other types. just put in the key the name of the object and in the value his class (without this option you will get the document as it is) .

.. code-block:: python

foo = session.load("foos/1", object_type=Foo)

.. code-block:: python

class FooBar(object):
    def __init__(self,name,foo):
        self.name = name
        self.foo = foo

foo_bar = session.load("FooBars/1", object_type=FooBar, nested_object_types={"foo":Foo})

To load several documents at once, supply a list of ids to session.load.

.. code-block:: python

foo = session.load(["foos/1", "foos/2", "foos/3"], object_type=Foo)

Delete a document

To delete a document from the store, use session.delete() with the id or entity you would like to delete.

.. code-block:: python

with store.open_session() as session:
    foo = session.delete("foos/1")

Store a new document

to store a new document, use session.store(entity) with the entity you would like to store (entity must be an object) For storing with dict we will use database_commands the put command (see the source code for that).

.. code-block:: python

class Foo(object):
   def __init__(self, name, key = None):
       self.name = name
       self.key = key

class FooBar(object):
    def __init__(self, name, foo):
        self.name = name
        self.foo = foo

with store.open_session() as session:
    foo = Foo("PyRavenDB")
    session.store(foo)
    session.save_changes()

To save all the changes we made we need to call session.save_changes().

Query

• object_type - Give the object type you want to get from query.
• index_name - The name of index you want the query to work on (If empty the index will be dynamic).
• collection_name - Name of the collection (mutually exclusive with indexName).
• is_map_reduce - Whether we are querying a map/reduce index(modify how we treat identifier properties).
• wait_for_non_stale_results - False by default if True the query will wait until the index will be non stale.
• default_operator - The default query operator (OR or AND).
• with_statistics - when True the qury will return stats about the query.
• nested_object_types - A dict of classes for nested object the key will be the name of the class and the value will be the object we want to get for that attribute

.. code-block:: python

with store.open_session() as session:
    query_result = list(session.query().where_equals("name", "test101")
    query_result = list(session.query(object_type=Foo).where_starts_with("name", "n"))
    query_result = list(session.query(object_type=Foo).where_ends_with("name", "7"))
    query_result = list(session.query(object_type=FooBar,nested_object_types={"foo":Foo}).where(name="foo_bar"))

You can also build the query with several options using the builder pattern.

.. code-block:: python

with store.open_session() as session:
    list(session.query(wait_for_non_stale_results=True).where_not_none("name").order_by_descending("name"))

For the query you can also use the where feature which can get a variable number of arguments (**kwargs)

.. code-block:: python

with store.open_session() as session:
    query_results = list(session.query().where(name="test101", key=[4, 6, 90]))

name and key are the field names for which we query

Includes

A list of the properties we like to include in the query or in load. The include property wont show in our result but when we load or query for it we wont requests it from the server. The includes will save on the session cache.

.. code-block:: python

class FooBar(object):
    def __init__(name, foo_key)
        self.name = name
        self.foo = foo_key

store =  document_store.DocumentStore(urls=["http://localhost:8080"], database="PyRavenDB")
store.initialize()

with store.open_session() as session:
    query_result = list(session.query().where_equals("name", "testing_includes").include("foo")
    foo_bar = session.load("FooBars/1", object_type=FooBar, includes=foo)

Changes Api

The RavenDB client offers a push notification feature that allows you to receive messages from a server about events that occurred there. You are able to subscribe to events for all documents, indexes and operations as well as to indicate a particular one that you are interested in. This mechanism lets you notify users if something has changed without the need to do any expensive polling.

Example:

.. code-block:: python

with document_store.DocumentStore(urls=["http://localhost:8080"], database="PyRavenDB") as store:
    store.initialize()
    documents = []
    indexes = []

    observer = store.changes().for_all_documents()
    observer.subscribe(documents.append)
    observer.ensure_subscribe_now()

    observer = store.changes().for_index('Users')
    observer.subscribe(ActionObserver(on_next=indexes.append))
    observer.ensure_subscribe_now()

    index_definition_users = IndexDefinition("Users", "from doc in docs.Users select new {doc.Name}")
    index_definition_dogs = IndexDefinition("Dogs", "from doc in docs.Dogs select new {doc.brand}")

    store.maintenance.send(PutIndexesOperation(index_definition_dogs, index_definition_users))

    with store.open_session() as session:
        session.store(User("Idan"), key="users/1")
        session.save_changes()

In this example we want to observe to changes from all documents and for index with the name of Users. After we register the observable we can subscribe for the notification and decide what to do with them (like append).

If you did not create an Observer for the subscription we will create one for you with the method you put. (To create Observer you can make any class that you want that will inherit from the class Observer can be found in pyravendb.changes.observers or to use the ActionObserver).

.. code-block:: python

class Observer(metaclass=ABCMeta):
    @abstractmethod
    def on_completed(self):
        pass

    @abstractmethod
    def on_error(self, exception):
       pass

    @abstractmethod
    def on_next(self, value):
       pass

What`s new

Mappers

mappers have been added to DocumentConvention to be able to parse custom objects. For using the mappers, only update conventions.mappers from the DocumentStore with your own dict. The key of the mappers will be the type of the object you want to initialize and the value will be a key, value method: the key will be the property name inside the object and the value will be the value of the property inside the document. like before you must specify the object_type property to be able to fetch the mapper method that you supplied if nested_object_types is initialized the mappers won't work.

Example:

.. code-block:: python

class Address:
    def __init__(self, street, city, state):
        self.street = street
        self.city = city
        self.state = state


class Owner:
    def __init__(self, name, address):
        self.name = name
        self.address = address


class Dog:
    def __init__(self, name, owner):
        self.name = name
        self.owner = owner

# This method will be called for each of the object properties
def get_dog(key, value):
    if not value:
        return None
    if key == "address":
        return Address(**value)
    elif key == "owner":
        return Owner(**value)


address = Address("Rub", "Unknown", "Israel")
owner = Owner("Idan", address)
dog = Dog(name="Donald", owner=owner)

with DocumentStore(urls=["http://localhost:8080"], database="PyRavenDB") as store:
    store.conventions.mappers.update({Dog: get_dog})
    store.initialize()
    with store.open_session() as session:
        result = session.load("dogs/1-A", object_type=Dog)

Bug Tracker

http://issues.hibernatingrhinos.com/issues/RDBC