请教一个关于模糊查询来过滤数据的sql语句
需要对表A中的a字段来进行条件过滤，
原来的写法就是 not like '%x%',not like '%xx%',not like '%xxx%'这样，每次手工改程序，
觉得改程序麻烦，想建一个表保存过滤条件，用来进行模糊过滤，
达到类似not in （select *） 的目的，请高手指点。
[解决办法]
with test as (
select 'x' as str from dual
union all
select 'xx' as str from dual
union all
select 'xxx' as str from dual
)
select * from test where regexp_like(str,'x+')

=========================
1x
2xx
3xxx
[解决办法]

declare
v_str_like varchar2(2000);
begin
for c in ( select 'x' as str from dual
 union all
 select 'xx' as str from dual
 union all
 select 'xxx' as str from dual)
loop
v_str_like:=v_str_like
[解决办法]
'not like ''%'
[解决办法]
c.str
[解决办法]
'%'',';
end loop; 
dbms_output.put_line(RTrim(v_str_like, ','));
end;