如何用存储过程实现两个表同步？

Question

现在又两个表分别是A表（ a ，b ， c ，d ， e ，f） B表（a，b，c，d）现在点击同步按钮，将A表的数据复制到B表，A，B两个同字段的，数据使用A表的数据（A，B当然通过主键关联），如果说A.a = B.a 剩下A表的数据要全部插入到B表！

Answer 1

update set B b=A.b,c=A.c,d=A.d from A where B.a=A.a

insert into B(a,b,c,d) select A.a,A.b,A.c,A,d from A where A.a not in(select a from B)

for c in (select a,b,c,d from A left join B on A.a=B.a) loop
     update B set b=c.b,c=c.c,d=c.d where a=c.a;
end loop;
insert into B(a,b,c,d) select A.a,A.b,A.c,A,d from A where A.a not in(select a from B);

Answer 2

update set B b=A.b,c=A.c,d=A.d from A where B.a=A.a

insert into B(a,b,c,d) select A.a,A.b,A.c,A,d from A where A.a not in(select a from B)

for c in (select a,b,c,d from A left join B on A.a=B.a) loop
     update B set b=c.b,c=c.c,d=c.d where a=c.a;
end loop;
insert into B(a,b,c,d) select A.a,A.b,A.c,A,d from A where A.a not in(select a from B);