UPDATE B SET B.KHID=(select max(A.KHID) from A WHERE B.SBLBID=A.SBLBID AND B.SBYJH=A.SBYJH) where exists(select A.KHID from A WHERE B.SBLBID=A.SBLBID AND B.SBYJH=A.SBYJH);
update b set b.khid=a.khid from a,b where a.sblbid=a.sblbid and b.sbyjh=a.sbyjh and b.khid=a.khid
Update 表2 B SET B.KHID=(Select A.KHID From 表1 A WHERE B.SBLBID=A.SBLBID AND B.SBYJH=A.SBYJH);
where exists(select A.KHID from A WHERE B.SBLBID=A.SBLBID AND B.SBYJH=A.SBYJH);