就是当B表中的ID1和A表的ID1相同时就要实现
A表中的NUM1和B表中的BUM2相加
--------------------------
select a.id1,amount=num1+num2 from a,b where a.id1=b.id1若B中没有A中那条纪录的话就往B中添加那条纪录
-----------------------------------
insert into b(num2,id1)
select num1,a.id1 from a,b where a.id1 not in (select id1 from b)
A表中的NUM1和B表中的BUM2相加
--------------------------
select a.id1,amount=num1+num2 from a,b where a.id1=b.id1若B中没有A中那条纪录的话就往B中添加那条纪录
-----------------------------------
insert into b(num2,id1)
select num1,a.id1 from a,b where a.id1 not in (select id1 from b)
update a set num1=num1+num2 from b where a.id1=b.id1
UPDATE B SET NUM2=NUM2+NUM1
FROM A, B
WHERE A.ID1 = B.ID1-- 若B中没有A中那条纪录的话就往B中添加那条纪录
INSERT B(NUM2, ID1) SELECT * FROM NUM1, ID1 FROM A
WHERE NOT EXISTS(
SELECT * FROM B WHERE ID1=A.ID1)
FROM A, B
WHERE A.ID1 = B.ID1 --- 这里不是比较了吗? 数据库的处理就是这样的, 遍历是数据库自己去完成的事, 不用你定义记录集(毕竟数据库不是程序)