Oracle 21c

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create table Employee (
  Id varchar(50),
  Name varchar(20)
);
insert into Employee
select 'I1BF91860BCB711EDBF4EF0FBCBCA9E17' as Id,	'Tim' as Name from dual
  union all
select 'I1BF91860BCB711EDBF4EF0FBCBCA9E18',	'Sam' from dual
  union all
select 'I1BF91860BCB711EDBF4EF0FBCBCA9E19',	'Rohan' from dual
3 rows affected

create table Trainings (
  Id	varchar(50),
  Name	varchar(20),
  Employee_Id varchar(50)
);
insert into Trainings
select 'I1BF91860BCB711EDBF4EF0FBCBCA9P10' as Id,	'Java Basics' as Name,	'I1BF91860BCB711EDBF4EF0FBCBCA9E17' as EmployeeId from dual 
union all
select 'I1BF91860BCB711EDBF4EF0FBCBCA9P11',	'Angular',	'I1BF91860BCB711EDBF4EF0FBCBCA9E17' from dual
union all
select 'I1BF91860BCB711EDBF4EF0FBCBCA9P12',	'DotNet',	'I1BF91860BCB711EDBF4EF0FBCBCA9E18' from dual
3 rows affected

select e.Id, max(e.Name) as Name, listagg(t.NAME, ',') as training
from Employee e
left join Trainings t on t.Employee_Id = e.Id
group by e.Id
order by e.Id


ID
NAME
TRAINING


I1BF91860BCB711EDBF4EF0FBCBCA9E17
Tim
Java Basics,Angular

I1BF91860BCB711EDBF4EF0FBCBCA9E18
Sam
DotNet

I1BF91860BCB711EDBF4EF0FBCBCA9E19
Rohan
null

ID	NAME	TRAINING
I1BF91860BCB711EDBF4EF0FBCBCA9E17	Tim	Java Basics,Angular
I1BF91860BCB711EDBF4EF0FBCBCA9E18	Sam	DotNet
I1BF91860BCB711EDBF4EF0FBCBCA9E19	Rohan	null