UPDATE S_fangyuanxinxi

SET wuyeleixing =
(SELECT s_dalou.yongtu
FROM s_dalou
WHERE s_fangyuanxinxi.loupanmingcheng = s_dalou.loupanmingcheng AND
s_fangyuanxinxi.donghao = s_dalou.mingcheng)

多表关联更新sql