select substr(a,instr(a,'_',1,1)+1,instr(a,'_',1,2)-instr(a,'_',1)-1)
from
( select 'D:\CALLCENTER2\20111025\20111025092838_13003120212_DY190.MP3' a from dual )
from
( select 'D:\CALLCENTER2\20111025\20111025092838_13003120212_DY190.MP3' a from dual )
根据这个地址你所定义的属性名
select sbustr(属性名,instr(a,'_',1)+1,instr(属性名,'_',2)-instr(属性名,'_',1)-1) from 表名 where 条件