一个表字段赋值到另一个表

mysql

update m a,n b set a.a001703=TIMESTAMPDIFF ( YEAR, a.A001041, CURDATE() ) - ifnull ( b.A241704, 0 ) where a.id=b.id and a.A001041 !=''、

oracle

update (select A.sfmj mj1,B.sfmj mj2 from sf_jmmj_t A,sf_jmyh_t B where A.yhbh=B.yhbh) C set C.MJ1=C.MJ2