Infinidat/infi.clickhouse_orm
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M1ha 2017-01-26 15:48:01 +05:00
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@ -189,9 +189,9 @@ Field Types
Currently the following field types are supported: Currently the following field types are supported:
============= ======== ================= =================================================== =================== ======== ================= ===================================================
Class DB Type Pythonic Type Comments Class DB Type Pythonic Type Comments
============= ======== ================= =================================================== =================== ======== ================= ===================================================
StringField String unicode Encoded as UTF-8 when written to ClickHouse StringField String unicode Encoded as UTF-8 when written to ClickHouse
DateField Date datetime.date Range 1970-01-01 to 2038-01-19 DateField Date datetime.date Range 1970-01-01 to 2038-01-19
DateTimeField DateTime datetime.datetime Minimal value is 1970-01-01 00:00:00; Always in UTC DateTimeField DateTime datetime.datetime Minimal value is 1970-01-01 00:00:00; Always in UTC
@ -208,7 +208,9 @@ Float64Field Float64 float
Enum8Field Enum8 Enum See below Enum8Field Enum8 Enum See below
Enum16Field Enum16 Enum See below Enum16Field Enum16 Enum See below
ArrayField Array list See below ArrayField Array list See below
============= ======== ================= =================================================== AliasField See below See below See below
MaterializedField See below See below See below
=================== ========== ================= ===================================================
Working with enum fields Working with enum fields
************************ ************************
@ -249,6 +251,40 @@ You can create array fields containing any data type, for example::
data = SensorData(date=date.today(), temperatures=[25.5, 31.2, 28.7], humidity_levels=[41, 39, 66]) data = SensorData(date=date.today(), temperatures=[25.5, 31.2, 28.7], humidity_levels=[41, 39, 66])
Working with materialized and alias fields
******************************************
ClickHouse provides an opportunity to create MATERIALIZED and ALIAS Fields.
See documentation `here <https://clickhouse.yandex/reference_en.html#Default values>`.
Both field types can't be inserted into database directly.
These field values are ignored, when using database.insert() method.
These fields are set to default values if you use database.select('SELECT * FROM mymodel', model_class=MyModel),
because ClickHouse doesn't return them.
Nevertheless, attribute values (as well as defaults) can be set for model object from python.
Usage::
class Event(models.Model):
created = fields.DateTimeField()
created_date = fields.MaterializedField(fields.DateTimeField(), 'toDate(created)')
name = StringField()
username = AliasField(StringField(), 'name')
engine = engines.MergeTree('created_date', ('created_date', 'created'))
obj = Event(created=datetime.now(), name='MyEvent')
db = Database('my_test_db')
db.insert([obj])
# All values will be retrieved from database
db.select('SELECT created, created_date, username, name FROM $db.event', model_class=Event)
# created_date, username will contain default value
db.select('SELECT * FROM $db.event', model_class=Event)
Table Engines Table Engines
------------- -------------