1、select decode(a.xh,'','0','1')||decode(b.xh,'','0','1') from A a left join B b on a.xh=b.xh where a.xh='" + xh + "'
查找在xh是否在A、B中如在在返回1，不在返回0。
2、update A set bh=(select bh from B where B.id= A.id) where id in (select id from B)
更新A 、编号在B中而且在A中
3、insert into A (id,bh) select id,bh from B where id not in(select id from A
更新A、编号在B中而且不再A中