To update CLOB column in Oracle

Question

I need to update table B with column Value with CLOB type from table A

Table A

ID    Value
1001  ABC
1002  CDE
1003  ABC
1004  PWD

Table B to be updated as below:

ID - varchar2(355)
Value - CLOB

ID  Value
ABC 1001!1003
CDE 1002
PWD 1004

Answer 1

Looks more like an INSERT , not UPDATE . Anyway, LISTAGG will help in both cases.

SQL> insert into b (id, value)
  2  select a.value, listagg(a.id, '!') within group (order by a.id)
  3  from a
  4  group by a.value;

3 rows created.

SQL> select * From b;

ID         VALUE
---------- --------------------------------------------------
ABC        1001!1003
CDE        1002
PWD        1004

SQL>