The reason for the error was that I opened the connection to the database wrong.
I did: con = cql.connect(host, port, keyspace) but correct is: con = cql.connect(host, port, keyspace, cql_version='3.0.0') Now it works fine. Thanks for reading. 2013/1/24 aaron morton <aa...@thelastpickle.com>: > How did you create the table? > > Anyways that looks like a bug, I *think* they should go here > http://code.google.com/a/apache-extras.org/p/cassandra-dbapi2/issues/list > > Cheers > > ----------------- > Aaron Morton > Freelance Cassandra Developer > New Zealand > > @aaronmorton > http://www.thelastpickle.com > > On 24/01/2013, at 7:14 AM, Paul van Hoven <paul.van.ho...@googlemail.com> > wrote: > > I try to access my local cassandra database via python. Therefore I > installed db-api 2.0 and thrift for accessing the database. Opening > and closing a connection works fine. But a simply query is not > working: > > The script looks like this: > > c = conn.cursor() > c.execute("""select * from users;""") > data = c.fetchall() > print "Query: select * from users; returned the following result:" > print str(data) > > > The table users looks like this: > qlsh:demodb> select * from users; > > user_name | birth_year | gender | password | session_token | state > -----------+------------+--------+----------+---------------+------- > jsmith | null | null | secret | null | null > > > > But when I try to execute it I get the following error: > Open connection to localhost:9160 on keyspace demodb > Traceback (most recent call last): > File > "/Users/Tom/Freelancing/Company/Python/ApacheCassandra/src/CassandraDemo.py", > line 56, in <module> > perfromSimpleCQLQuery() > File > "/Users/Tom/Freelancing/Company/Python/ApacheCassandra/src/CassandraDemo.py", > line 46, in perfromSimpleCQLQuery > c.execute("""select * from users;""") > File "/Library/Python/2.7/site-packages/cql/cursor.py", line 81, in execute > return self.process_execution_results(response, decoder=decoder) > File "/Library/Python/2.7/site-packages/cql/thrifteries.py", line > 116, in process_execution_results > self.get_metadata_info(self.result[0]) > File "/Library/Python/2.7/site-packages/cql/cursor.py", line 97, in > get_metadata_info > name, nbytes, vtype, ctype = self.get_column_metadata(colid) > File "/Library/Python/2.7/site-packages/cql/cursor.py", line 104, in > get_column_metadata > return self.decoder.decode_metadata_and_type(column_id) > File "/Library/Python/2.7/site-packages/cql/decoders.py", line 45, > in decode_metadata_and_type > name = self.name_decode_error(e, namebytes, > comptype.cql_parameterized_type()) > File "/Library/Python/2.7/site-packages/cql/decoders.py", line 29, > in name_decode_error > % (namebytes, expectedtype, err)) > cql.apivalues.ProgrammingError: column name '\x00\x00\x00' can't be > deserialized as 'org.apache.cassandra.db.marshal.CompositeType': > global name 'self' is not defined > > I'm not shure if this is the right place to ask for: But am I doing > here something wrong? > >
