Sql query to achieve this

Question

Hi all,
Query to achieve the below output:
source table :
empno,_deptno_
110,10
110,20
110,30
120,10
130,20
130,30
130,30
110,40
I need the output in below format:
empno,deptno
110,10$20$30$40
120,10
130,20$30$30

Answer 1

or:
SQL> -- generating sample data:
SQL> with t as (
  2  select 110 empno,10 deptno from dual union
  3  select 110,20 from dual union
  4  select 110,30 from dual union
  5  select 120,10 from dual union
  6  select 130,20 from dual union
  7  select 130,30 from dual union
  8  select 130,30 from dual union
  9  select 110,40 from dual
10  )
11  --
12  -- actual query:
13  --
14  select empno
15  ,      replace(sys_connect_by_path(deptno, ','),',') deptno
16  from ( select empno
17         ,      deptno
18         ,      row_number() over (partition by empno order by deptno) rn
19         from    t
20       )
21  where connect_by_isleaf=1    
22  start with rn=1
23  connect by empno=prior empno
24         and rn = prior rn+1;
     EMPNO DEPTNO
       110 10203040
       120 10
       130 2030
3 rows selected.