collections - map update in cassandra with cql3 -

i have cf in cassandra have coulmn type map

this cf below:

create table word_cat (     word text,     doc_occurrence map <text, int >,    total_occurrence map <text, int >,       primary key (word) ); 

i want update doc_occurrence value of key pluse new number.i want in 1 query.

i think in can done in query this:

update word_cat set doc_occurrence ['key']=doc_occurrence ['key']+5 word='name'; 

but not work, can body help?

better explain example, considering schema.

now here inserting data, followed output

cqlsh:ks1> update word_cat set            ...  doc_occurrence=            ...  {'cassandra' : 1}            ...  word ='name'; cqlsh:ks1> select * word_cat ;   word | doc_occurrence | total_occurrence ------+----------------+------------------  name | {cassandra: 1} |             null 

now if want overwrite existing key (cassandra value 5) in map, here go

cqlsh:ks1> update word_cat set            ...  doc_occurrence=            ...  {'cassandra' : 5}            ...  word ='name';  cqlsh:ks1> select * word_cat ;   word | doc_occurrence | total_occurrence ------+----------------+------------------  name | {cassandra: 5} |             null 

update:

the functionality referring in comment including counter value in map. unfortunately counters not allowed inside collection, rather not supported yet. may can have separate counter column family handle things.