How to update clustering key in cassandra using update query?

Question

This is my table structure and I am updating the sequence with the following query:

Update styles set sequence=1 where styleid = 'CLASSIC';

I am getting error message as

PRIMARY KEY part sequence found in SET part
Missing PRIMARY KEY part sequence

CREATE TABLE styles (
  styleid ascii,
  sequence int,
  active boolean,
  image ascii,
  name ascii,
  PRIMARY KEY (styleid, sequence)
) WITH CLUSTERING ORDER BY (sequence DESC);

Please anyone help me to update the clustering key sequence so that it will be updated. Or any alternative method please share.

Solution

Based on how Cassandra stores the data, updating clustering columns (Primary key) is not possible.

Rowkey which is a combination of **styleid** ->[sequence] -> [active boolean,image ascii, name ascii]

In order to point non-primary columns for updating/deleting, it needs to parse through styleid -> sequence partition to hit the columns.

Primary key once created can't be changed as it represents how data is stored in Cassandra. Hence updating 'sequence' here is not possible.