How to query for a set type cassandra column using python?

[凸鎚大法師]

How to query for a set type cassandra column using python?

My cassandra table has a column of type legs set<int>.

ex:

CREATE TABLE ptt_spider.useridindex (

    userid text PRIMARY KEY,

    cd_idx set<int>,

    pd_idx set<int>,

    udindex set<int>

) 

I am using following python code for query data from my cassandra database:

from cassandra.cluster import Cluster

from cassandra.cqlengine import columns

from cassandra.cqlengine.models import Model

from cassandra.cqlengine import connection

class UserIdIndex(Model):

    __table_name__  = 'useridindex'

    __keyspace__ = 'TestDB'

    __connection__ = 'cluster2'

    userid = columns.Text(primary_key=True)

    UDIndex = columns.Set(columns.UUID())

    pd_Idx = columns.Set(columns.Integer())

    cd_Idx = columns.Set(columns.Integer())

    

def cassandraTest():

    cluster = Cluster(contact_points=['localhost'],port=9042)

    session = cluster.connect('TestDB')

 

    connection.register_connection('cluster2', session=session)

    

    querySet = UserIdIndex.objects.filter(userid='a5981826')

    user = querySet.get()

    for item in user.UDIndex:

        print(item)

        

if __name__ == '__main__':

    cassandraTest()

When I pass a query for selecting the columns of type text, it works fine but if I try to select a set type column, it throws an error:

# ERROR :

# Traceback (most recent call last):

#   File "/home/jack/PythonProject/main/KeywordSearch/test.py", line 114, in <module>

#     cassandraTest()

#   File "/home/jack/PythonProject/main/KeywordSearch/test.py", line 106, in cassandraTest

#     for item in user.UDIndex:

# TypeError: 'type' object is not iterable

please help me , thank you!

[jaume.m...@datastax.com]

Hello,

The CREATE query you have posted doesn't correspond to the table in the script, that may be the reason, but this script works for me:

from cassandra.cluster import Cluster
from cassandra.cqlengine import columns
from cassandra.cqlengine.models import Model
from cassandra.cqlengine import connection

from cassandra.cqlengine.management import sync_table, create_keyspace_simple

from uuid import uuid4

class UserIdIndex(Model):
    __table_name__ = 'useridindex'

    __keyspace__ = 'testdb'

    __connection__ = 'cluster2'
    userid = columns.Text(primary_key=True)

    udindex = columns.Set(columns.UUID())
    pd_idx = columns.Set(columns.Integer())
    cd_idx = columns.Set(columns.Integer())

def cassandraTest():
    cluster = Cluster(contact_points=['localhost'], port=9042)

    session = cluster.connect()


    connection.register_connection('cluster2', session=session)
    create_keyspace_simple('testdb', 1, connections=['cluster2'])
    sync_table(UserIdIndex)

    UserIdIndex.create(userid='a5981826', pd_idx={1, 2, 3}, cd_idx={6, 7, 8}, udindex={uuid4(), uuid4(), uuid4()})

    querySet = UserIdIndex.objects.filter(userid='a5981826')
    user = querySet.get()

    for item in user.udindex:

        print(item)


if __name__ == '__main__':
    cassandraTest()

Enter code here...

Jaume

[凸鎚大法師]

you are right , thank your help

[Sovanna]

I've updated your code on http://collabedit.com/xkt2h

--

Sovanna HING

"Love people and use things" - Minimalism

On Mon, Mar 26, 2018 at 11:52 AM, 凸鎚大法師 <arlia...@gmail.com> wrote:

How to query for a set type cassandra column using python?
My cassandra table has a column of type legs set<int>.

ex:
CREATE TABLE ptt_spider.useridindex (
    userid text PRIMARY KEY,
    cd_idx set<int>,
    pd_idx set<int>,
    udindex set<int>
)

I am using following python code for query data from my cassandra database:

http://collabedit.com/xkt2h

When I pass a query for selecting the columns of type text, it works fine but if I try to select a set type column, it throws an error:

# ERROR :
# Traceback (most recent call last):
#   File "/home/jack/PythonProject/main/KeywordSearch/test.py", line 114, in <module>
#     cassandraTest()
#   File "/home/jack/PythonProject/main/KeywordSearch/test.py", line 106, in cassandraTest
#     for item in user.UDIndex:
# TypeError: 'type' object is not iterable         

please help me , thank you!

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