ORACLEA表根据B表字段更新

update product_info t set (t.salename,t.xsqy)=(select c.salename,c.xsqy from contract_erp c where c.contractcode=t.contractid)
where t.contractid in(select c.contractcode from contract_erp c) and t.contractid is not null and t.salename is null;