Help with PL/SQL - CLOB

[anyoneokay]

The operation of clob is different from other data types.
If you want to insert or update a clob column, you must do as below:
(1) you must go to the clob row firstly;
(2) then you can update clob column used by dbms_lob package(such as dbms_lob.write, dbms_lob.write, dbms_lob.writeappend);

Here is an easy example:
--------------------------------------------------------

create table t_clob2
(
  no      number,
  content clob
);

create or replace procedure sp_clob(ip_no number,ip_content varchar2)
is
  lv_no      number;
  lv_clob    clob;
  lv_sqlstr  varchar2(4000);
begin
  insert into t_clob2 values(ip_no,empty_clob());
  commit;
  lv_sqlstr := 'select content from t_clob2 where no=' || ip_no || ' for update';
  execute immediate lv_sqlstr into lv_clob;
  dbms_lob.write(lv_clob,length(ip_content),1,ip_content);
  commit;
end;

SQL> exec sp_clob(1,'abcdefg');
 
PL/SQL procedure successfully completed
 
SQL> select * from t_clob2;
 
        NO CONTENT
--------------------------------------------------------------------------
         1 abcdefg
/