It's not currently supported in CQL 
https://issues.apache.org/jira/browse/CASSANDRA-3761

You can do it using the CLI, see the online help. 

Cheers


-----------------
Aaron Morton
Freelance Developer
@aaronmorton

On 2/03/2012, at 10:39 AM, Bayle Shanks wrote:

hi, i'm wondering how to do composite data
storage types in CQL. I am trying to mimic the Composite Types
functionality of the Pycassa client:

http://pycassa.github.com/pycassa/assorted/composite_types.html


In short, in Pycassa you can do something like:

---

itemTimeCompositeType = CompositeType(UTF8Type(), LongType())

pycassa.system_manager.SystemManager().create_column_family(
 keyspaceName,
 columnFamilyName,
 key_validation_class=itemTimeCompositeType
)

...

columnFamily.insert(self._makeKey(item, time_as_integer), {field : value})

---


and then your primary key for this column family is a pair of a string
and an integer. This is important because i am using
ByteOrderedPartitioner and doing range scans among keys which share
the same string 'item' but have different values for the integer.

My motivation is that i am trying to port
https://github.com/bshanks/cassandra-timeseries-py to Ruby and i
thought i might try CQL.

thanks,
 bayle