Oracle 利用sequence实现递增

第一次学着写存储过程，请多提意见，多指正，谢谢 实现目的：向表中插入从StartSerialNo到EndSerialNo的NumInsert条重复数据，表中仅visaserialno字段递增，其余字段内容重复。 该存储过程用动态sql拼接的方式，创建该存储过程，先判断序列是否存在，若存在则

第一次学着写存储过程，请多提意见，多指正，谢谢
实现目的：向表中插入从StartSerialNo到EndSerialNo的NumInsert条重复数据，表中仅visaserialno字段递增，其余字段内容重复。  该存储过程用动态sql拼接的方式，创建该存储过程，先判断序列是否存在，若存在则删除后新建

--创建存储过程 
CREATE OR REPLACE Procedure insert_vsunusedmark 
( VisaKindCode In varchar, 
StartSerialNo In Varchar, 
EndSerialNo In Varchar,
NumInsert In Varchar,
visapre In Varchar,
visacode In Varchar,
visaname In Varchar,
pressbatchno In Varchar,
businessno In Varchar,
visaamount In NUMBER,
usedate In DATE,
usertype In Varchar,
usercode In Varchar,
username In Varchar,
visastatus In Varchar,
providetimes In NUMBER,
recycletimes In NUMBER,
verifiedcancelflag In Varchar,
beforestatus In Varchar,
remark In Varchar,
flag In Varchar,
comcode In Varchar,
usedenddate In DATE,
forcecalldays In Varchar,
policypremium In NUMBER
) AS strsql varchar2(5000);
v_count int;
Begin
-- 判断sequence是否已存在，存在则删除重建
select count(1) into v_count from All_Sequences a where sequence_name = upper(VisaKindCode);
if v_count > 0 then
execute immediate 'drop sequence '||VisaKindCode;
end if;
-- Create sequence 
strsql := 'create sequence '||VisaKindCode||' 
minvalue '||StartSerialNo||' 
maxvalue '||EndSerialNo||' 
start with '||StartSerialNo||' 
increment by 1 
cache 20'; 
execute immediate strsql; 
strsql := 
'insert into vsunusedmark 
( visaserialno, 
visapre, 
visacode, 
visaname, 
pressbatchno, 
businessno, 
visaamount, 
usedate, 
usertype, 
usercode, 
username, 
visastatus, 
providetimes, 
recycletimes, 
verifiedcancelflag, 
beforestatus, 
remark, 
flag, 
comcode, 
usedenddate, 
forcecalldays, 
policypremium) 
select '||VisaKindCode||'.NEXTVAL, 
'''||visapre||''',
'''||visacode||''', 
'''||visaname||''',
'''||pressbatchno||''',
'''||businessno||''',
'''||visaamount||''', 
'''||usedate||''', 
'''||usertype||''', 
'''||usercode||''', 
'''||username||''', 
'''||visastatus||''', 
'''||providetimes||''', 
'''||recycletimes||''', 
'''||verifiedcancelflag||''', 
'''||beforestatus||''', 
'''||remark||''', 
'''||flag||''', 
'''||comcode||''', 
'''||usedenddate||''', 
'''||forcecalldays||''', 
'''||policypremium||'''
from vsunusedmark v where rownum<='||NumInsert||''; 
execute immediate strsql;
exception
WHEN OTHERS THEN
--发生异常,回滚
rollback;
Commit; 
End insert_vsunusedmark;