Infinidat/infi.clickhouse_orm
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M1ha 2017-01-26 15:48:01 +05:00
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@ -189,26 +189,28 @@ Field Types
Currently the following field types are supported:
============= ======== ================= ===================================================
Class DB Type Pythonic Type Comments
============= ======== ================= ===================================================
StringField String unicode Encoded as UTF-8 when written to ClickHouse
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
Int8Field Int8 int Range -128 to 127
Int16Field Int16 int Range -32768 to 32767
Int32Field Int32 int Range -2147483648 to 2147483647
Int64Field Int64 int/long Range -9223372036854775808 to 9223372036854775807
UInt8Field UInt8 int Range 0 to 255
UInt16Field UInt16 int Range 0 to 65535
UInt32Field UInt32 int Range 0 to 4294967295
UInt64Field UInt64 int/long Range 0 to 18446744073709551615
Float32Field Float32 float
Float64Field Float64 float
Enum8Field Enum8 Enum See below
Enum16Field Enum16 Enum See below
ArrayField Array list See below
============= ======== ================= ===================================================
=================== ======== ================= ===================================================
Class DB Type Pythonic Type Comments
=================== ======== ================= ===================================================
StringField String unicode Encoded as UTF-8 when written to ClickHouse
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
Int8Field Int8 int Range -128 to 127
Int16Field Int16 int Range -32768 to 32767
Int32Field Int32 int Range -2147483648 to 2147483647
Int64Field Int64 int/long Range -9223372036854775808 to 9223372036854775807
UInt8Field UInt8 int Range 0 to 255
UInt16Field UInt16 int Range 0 to 65535
UInt32Field UInt32 int Range 0 to 4294967295
UInt64Field UInt64 int/long Range 0 to 18446744073709551615
Float32Field Float32 float
Float64Field Float64 float
Enum8Field Enum8 Enum See below
Enum16Field Enum16 Enum 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
************************
@ -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])
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
-------------