在存储过程中操作ORACLE CLOB字段

下面的 存储过程演示了大数据不能一次插入数据库的分批插入法，用到了ORACLE CLOB字段

CREATE OR REPLACE PROCEDURE INSERT_RES_PEOPLE_ADD
(
r_people_cname varchar2,
r_people_intro varchar2
)
AS
r_intro_clob clob;--
buffer varchar2(32767);
amount number := 2000;
offset number := 1;
BEGIN
select clobf into r_intro_clob from ztable where RES_CLASS_ID = 9;
if r_intro_clob is null then
update ztable set clobf = 'buffer' where RES_CLASS_ID = 9;

return ;
end if;

amount := dbms_lob.getlength(r_intro_clob);
dbms_lob.read(r_intro_clob,amount,offset,buffer);
buffer := buffer || r_people_intro;

update ztable set clobf = buffer where RES_CLASS_ID = 9;
EXCEPTION

when others then
rollback;
--raise;
return;
END;