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TRIVIAL pypi documentation
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README.rst
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README.rst
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@ -17,9 +17,7 @@ Usage
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Defining Models
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---------------
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Models are defined in a way reminiscent of Django's ORM:
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.. code:: python
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Models are defined in a way reminiscent of Django's ORM::
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from infi.clickhouse_orm import models, fields, engines
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@ -39,9 +37,7 @@ See below for the supported field types and table engines.
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Using Models
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------------
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Once you have a model, you can create model instances:
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.. code:: python
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Once you have a model, you can create model instances::
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>>> dan = Person(first_name='Dan', last_name='Schwartz')
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>>> suzy = Person(first_name='Suzy', last_name='Jones')
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@ -49,9 +45,7 @@ Once you have a model, you can create model instances:
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u'Dan'
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When values are assigned to model fields, they are immediately converted to their Pythonic data type.
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In case the value is invalid, a ``ValueError`` is raised:
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.. code:: python
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In case the value is invalid, a ``ValueError`` is raised::
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>>> suzy.birthday = '1980-01-17'
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>>> suzy.birthday
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@ -64,24 +58,18 @@ In case the value is invalid, a ``ValueError`` is raised:
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Inserting to the Database
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-------------------------
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To write your instances to ClickHouse, you need a ``Database`` instance:
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.. code:: python
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To write your instances to ClickHouse, you need a ``Database`` instance::
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from infi.clickhouse_orm.database import Database
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db = Database('my_test_db')
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This automatically connects to http://localhost:8123 and creates a database called my_test_db, unless it already exists.
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If necessary, you can specify a different database URL and optional credentials:
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.. code:: python
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If necessary, you can specify a different database URL and optional credentials::
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db = Database('my_test_db', db_url='http://192.168.1.1:8050', username='scott', password='tiger')
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Using the ``Database`` instance you can create a table for your model, and insert instances to it:
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.. code:: python
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Using the ``Database`` instance you can create a table for your model, and insert instances to it::
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db.create_table(Person)
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db.insert([dan, suzy])
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@ -91,18 +79,14 @@ The ``insert`` method can take any iterable of model instances, but they all mus
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Reading from the Database
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-------------------------
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Loading model instances from the database is simple:
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.. code:: python
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Loading model instances from the database is simple::
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for person in db.select("SELECT * FROM my_test_db.person", model_class=Person):
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print person.first_name, person.last_name
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Do not include a ``FORMAT`` clause in the query, since the ORM automatically sets the format to ``TabSeparatedWithNamesAndTypes``.
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It is possible to select only a subset of the columns, and the rest will receive their default values:
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.. code:: python
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It is possible to select only a subset of the columns, and the rest will receive their default values::
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for person in db.select("SELECT first_name FROM my_test_db.person WHERE last_name='Smith'", model_class=Person):
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print person.first_name
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@ -111,9 +95,7 @@ Ad-Hoc Models
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*************
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Specifying a model class is not required. In case you do not provide a model class, an ad-hoc class will
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be defined based on the column names and types returned by the query:
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.. code:: python
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be defined based on the column names and types returned by the query::
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for row in db.select("SELECT max(height) as max_height FROM my_test_db.person"):
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print row.max_height
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@ -124,9 +106,7 @@ you work with Pythonic column values and an elegant syntax.
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Counting
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--------
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The ``Database`` class also supports counting records easily:
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.. code:: python
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The ``Database`` class also supports counting records easily::
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>>> db.count(Person)
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117
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@ -161,27 +141,19 @@ Table Engines
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Each model must have an engine instance, used when creating the table in ClickHouse.
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To define a ``MergeTree`` engine, supply the date column name and the names (or expressions) for the key columns:
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.. code:: python
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To define a ``MergeTree`` engine, supply the date column name and the names (or expressions) for the key columns::
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engine = engines.MergeTree('EventDate', ('CounterID', 'EventDate'))
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You may also provide a sampling expression:
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.. code:: python
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You may also provide a sampling expression::
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engine = engines.MergeTree('EventDate', ('CounterID', 'EventDate'), sampling_expr='intHash32(UserID)')
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A ``CollapsingMergeTree`` engine is defined in a similar manner, but requires also a sign column:
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.. code:: python
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A ``CollapsingMergeTree`` engine is defined in a similar manner, but requires also a sign column::
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engine = engines.CollapsingMergeTree('EventDate', ('CounterID', 'EventDate'), 'Sign')
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For a ``SummingMergeTree`` you can optionally specify the summing columns:
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.. code:: python
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For a ``SummingMergeTree`` you can optionally specify the summing columns::
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engine = engines.SummingMergeTree('EventDate', ('OrderID', 'EventDate', 'BannerID'),
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summing_cols=('Shows', 'Clicks', 'Cost'))
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@ -189,9 +161,7 @@ For a ``SummingMergeTree`` you can optionally specify the summing columns:
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Data Replication
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****************
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Any of the above engines can be converted to a replicated engine (e.g. ``ReplicatedMergeTree``) by adding two parameters, ``replica_table_path`` and ``replica_name``:
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.. code:: python
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Any of the above engines can be converted to a replicated engine (e.g. ``ReplicatedMergeTree``) by adding two parameters, ``replica_table_path`` and ``replica_name``::
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engine = engines.MergeTree('EventDate', ('CounterID', 'EventDate'),
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replica_table_path='/clickhouse/tables/{layer}-{shard}/hits',
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@ -16,7 +16,6 @@ install_requires = [
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]
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version_file = src/infi/clickhouse_orm/__version__.py
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description = A Python library for working with the ClickHouse database
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long_description = A Python library for working with the ClickHouse database
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console_scripts = []
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gui_scripts = []
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package_data = []
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