You should use the dbms_lob
package, the procedure to add some string to the clob is dbms_lob.append
.
declare
c1 clob;
c2 varchar2(32000);
begin
c1 := 'abc';
c2 := 'text, which contains 32 000 characters';
dbms_lob.append(c1, c2);
c2 := 'some more text, which contains 32 000 characters';
dbms_lob.append(c1, c2);
insert into t1 values (c1);
end;