oracle数据库中查询一个表中的字段是否存在于另一个表中字段数据

select distinct(a.adcd),a.adnm from fda.ia_adc_adinfo a where not exists(select * from mde.sys_adcdyear b  where  a.adcd=b.code)  and  substr(a.adcd,5,2)!='00' and substr(a.adcd,7,15)='000000000'select distinct(a.adcd),a.adnm from fda.ia_adc_