不同数据库查询,然后通过单元格筛选进行关联可以吗select * from (select HDR.TAG_VALUE as 实际搅拌转速 from hme_data_record hdr, MT_TAG_B mtb, HME_EQUIPMENT_WORKCELL_REL mewr, hme_equipment he where mtb.tag_code =‘YZZPLSJJBZSFSG’—’YZZPLSJFSZSFSG’实际分散转速’;’YZZPLFSDLFSG’分散电流; ‘YZZPLJBDLFSG’搅拌电流;’YZZPLWDFSG’温度;’YZZPLJLCCZKDFSG’浆料存储真空度 and mtb.tag_id =hdr.tag_id and he.equip_num = '3030AN11ZNHG001'--'3030AN11ZNHG002'与前面的设备号一直 and he.equipment_id=mewr.equipment_id and hdr.workcell_id=mewr.workcell_id order by hdr.record_date desc) where rownum <2hdr是分库,其他是主库,这种跨库查询怎么实现