Group by on Primary Partition - cassandra

Question

I am not able to perform Group by on a primary partition. I am using Cassandra 3.10. When I group by I get the following error.
InvalidReqeust: Error from server: code=2200 [Invalid query] message="Group by currently only support groups of columns following their declared order in the Primary Key. My column is a primary key even still I am facing the problem.
My schema is
Table trends{
name text,
price int,
quantity int,
code text,
code_name text,
cluster_id text
uitime timeuuid,
primary key((name,price),code,uitime))
with clustering order by (code DESC, uitime DESC)
And the command that I run is: select sum(quantity) from trends group by code;

Answer 1

For starters your schema is invalid. You cannot set clustering order on code because it is the partition key. The order is going to be determined by the hash of it (unless using byte order partitioner - but don't do that).
The query and thing your talking about does work though. For example you can run
> SELECT keyspace_name, sum(partitions_count) AS approx_partitions FROM system.size_estimates GROUP BY keyspace_name;
keyspace_name | approx_partitions
--------------------+-------------------
system_auth | 128
basic | 4936508
keyspace1 | 870
system_distributed | 0
system_traces | 0
where they schema is:
CREATE TABLE system.size_estimates (
keyspace_name text,
table_name text,
range_start text,
range_end text,
mean_partition_size bigint,
partitions_count bigint,
PRIMARY KEY ((keyspace_name), table_name, range_start, range_end)
) WITH CLUSTERING ORDER BY (table_name ASC, range_start ASC, range_end ASC)
Perhaps the pseudo-schema you provided differs from the actual one. Can you provide output of describe table xxxxx in your question?