Create UDF and UDA in Cassandra

create_UDF_and_UDA_in_Cassandra.cqlsh

cqlsh:test_ks>
 
CREATE TABLE emp_dept_info(emp_id int, 
                           emp_name text, 
                           dept_id int, 
                           created_time timeuuid, 
                           PRIMARY KEY((emp_id), created_time));

# Insert data in emp_dept_info Table
 
INSERT INTO emp_dept_info(emp_id, emp_name, dept_id, created_time) 
VALUES(1, 'Venkat', 30, NOW());
INSERT INTO emp_dept_info(emp_id, emp_name, dept_id, created_time) 
VALUES(2, 'Gowri', 30, NOW());
INSERT INTO emp_dept_info(emp_id, emp_name, dept_id, created_time) 
VALUES(2, 'Sai', 30, NOW());
INSERT INTO emp_dept_info(emp_id, emp_name, dept_id, created_time) 
VALUES(2, 'Rakesh', 40, NOW());
INSERT INTO emp_dept_info(emp_id, emp_name, dept_id, created_time) 
VALUES(2, 'Kumar', 40, NOW());
INSERT INTO emp_dept_info(emp_id, emp_name, dept_id, created_time) 
VALUES(2, 'Varanasi', 50, NOW());
 
# Created the user-defined function
 
CREATE FUNCTION state_count_per_group( state map<int, int>, type int )
CALLED ON NULL INPUT
RETURNS map<int, int>
LANGUAGE java AS '
Integer count = (Integer) state.get(type);  
if (count == null) count = 1; 
else count++; state.put(type, count); 
return state; ' ;
 
# Created the below aggregate function using above function
 
CREATE OR REPLACE AGGREGATE agg_count_per_group(int)
SFUNC state_count_per_group
STYPE map<int, int>
INITCOND {};
 
cqlsh> SELECT agg_count_per_group(dept_id) FROM emp_dept_info;