Oracle 21c

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create table emp(
id number(10),
name varchar(30),
Qualification varchar(30),
Experience number(10))
;
create table task(
Task_Name varchar(30),
id number(10),
duration number(10),
wage number(10));
INSERT ALL
   INTO emp VALUES (1,'Aaron','Eng',	   2 )
   INTO emp VALUES (2,'Jacob','CS',	   3 )
   INTO emp VALUES (3,'Jehan','Art',	   1 )
   INTO emp VALUES (4,'Jenny','Math',	   7 )
SELECT 1 FROM DUAL;
4 rows affected

INSERT ALL
INTO task VALUES('clean', 1, 200, 50 )
INTO task VALUES('clean', 3, 200, 50 )
INTO task VALUES('wash', 4, 300, 200)
INTO task VALUES('decor', 1, 250, 300)
INTO task VALUES('decor', 2, 250, 300)
INTO task VALUES('decor', 4, 250, 300)
INTO task VALUES('errands', 2, 150, 150)
INTO task VALUES('errands', 4, 150, 150)
SELECT 1 FROM DUAL;
8 rows affected

with tab1 as (select * from emp e join task t
on e.id=t.id)
select task_name,
 LISTAGG(e.name, ',') WITHIN GROUP (
                  ORDER BY e.name) name_list, max(duration) duration, max(wage) wage from tab1 e group by task_name;


TASK_NAME
NAME_LIST
DURATION
WAGE


clean
Aaron,Jehan
200
50

decor
Aaron,Jacob,Jenny
250
300

errands
Jacob,Jenny
150
150

wash
Jenny
300
200

TASK_NAME	NAME_LIST	DURATION	WAGE
clean	Aaron,Jehan	200	50
decor	Aaron,Jacob,Jenny	250	300
errands	Jacob,Jenny	150	150
wash	Jenny	300	200