oracle统计无记录时写默认值
select nvl(max(t1.packagesize),0) www.2cto.com
from (
select decode(count(t.per_bus_code),0,'1') peoracle账号r_bus_code,decode(count(t.buss_code),0,'1') buss_code,decode(count(t.per_code),0,'1') per_code
from t_tybook_back_pers_business t
where t.per_code = 'TY-00000106'
and t.end_date > sysdate
and t.start_date<=sysdate ) t
left join t_tybook_before_business t1 on t.buss_code = t1.code
group by t.per_code;