Cassandra CQL Object Mapper for Python
cqlengine is a Cassandra CQL 3 Object Mapper for Python. cqlengine is part of the Datastax python driver for Cassandra
Questions tagged [cqlengine]
72 questions
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How to increment counter column through Cassandra python-driver ORM
I`m using this python driver. How can i increment counter using ORM in correct way?
Maybe smth like update(counter_value__add=1) or obj.counter_value += 1?
I try to avoid this manual query UPDATE ... SET counter_value = counter_value + 1
ubombi
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Cassandra. Default column value
Following example from python cassandra driver
class Users(Model):
username = columns.Text(index=True, required=True)
user_id = columns.UUID(index=True, default=uuid.uuid4)
email = columns.Text(primary_key=True, required=True)
passwd…
Nikolay Fominyh
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1 answer
Error with Cassandra's create_keyspace_simple
I'm trying to use cassandra to connect with Meetup streaming api through kafka. cqlengine seems like that it was an separated project before and the reference code that I am using is made around that time.
So before, cqlengine.management had…
user3368526
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1 answer
cassandra unable to create table keyerror
Im trying to create a table but get this error -
keyspace = cluster.metadata.keyspaces[ks_name]
KeyError: 'cqlengine'
Models:
import uuid
from cqlengine import columns
from cqlengine.models import Model
from datetime import datetime
from…
user1050619
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cqlengine connection set_session() not handling different keyspaces
I have the following code
from cassandra.cqlengine import connection
#inside a flask function
session = get_session_for_keyspace(keyspace)
connection.set_session(session)
object_list = ModelTable.objects.filter(....)
But although session…
Apostolos
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1 answer
How do I design this cassandra model properly?
I know the title is a bit broad, but I have tried a bunch of things with different errors, so I was going to use this space to describe each of them. I have a model in datastax's python-driver below:
class DIDSummary(Model):
__keyspace__ =…
Ethan Brouwer
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1 answer
cqlengine multilpe keyspaces
I am using cassandra from python 3.4.0 with cassandra-driver 2.5.0 (and cqlengine models) .
App data are distributed in: one keyspace for management and one keyspace per user. i need to query two keyspaces: master+custom.
I have coded a tiny class…
trilopin
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1 answer
cqlengine model default values and uuid
Working with cqlengine models i have found an unexpected behaviour with default_values and uuid.
I am using python 3.4, and cqlengine from cassandra-driver 2.5.0.
with following code:
from cassandra.cqlengine import columns, connection,…
trilopin
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1 answer
DataStax Enterprise 4.6.1 / C* Pagination in Python using cqlengine 0.21.0
I am currently trying to paginate query results from DSE 4.6.1 (Cassandra 2.0.12.200) with Python and cqlengine 0.21.0.
My table being queried is:
CREATE TABLE tags_for_search (
village_id int,
tag_prefix text,
tag text,
time timeuuid,
…
mbeacom
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1
vote
1 answer
json type in Cassandra data model?
I am wondering if I could have json data type in the column family:
My table will have a unique row key, and column name of "tweets_json" and column value of json content.
How would I create such a table in CQL/cassandra or using python Driver or…
brain storm
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3 answers
Querying with cqlengine
I am trying to hook the cqlengine CQL 3 object mapper with my web application running on CherryPy. Athough the documentation is very clear about querying, I am still not aware how to make queries on an existing table(and an existing keyspace) in my…
Abhiroop Sarkar
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1 answer
AttributeError: 'NoneType' object has no attribute '_consistency' when trying to show a list from database
I want to show a list from Cassandra database and show it in a html template usgin django. when I'm trying to show data it says: AttributeError: 'NoneType' object has no attribute '_consistency'
Views.py:
def music_list(request):
files =…
ehsan shirzadi
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Cassandra 2 - CQLEngine : Store Images error
I'm trying to store images in database.This is my code for get an Image :
image = Image.open(...a resource on web...)
imageData = StringIO.StringIO()
image.save(imageData, image.format)
myImage = imageData.getvalue()
But when trying to store in…
ABS
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how should i create table schema for product
so i want to create a table that are pointing to some row items (table) and number of row item i need to create that product
pname text,
pid timeuuid,
instock int,
req set
reqno set>>,
PRIMARY KEY (pname, pid)
or should…
itachi uchiha
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1 answer
Insert multiple rows in cqlengine
I am stucking on insert/update multiple rows /approximately 800 rows/ to cassandra table by cqlengine. I do not want to use loop in python. I searched and find batch query. But can not use it.
Please help me making batch query or give other…
Lkhagvasuren
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