A表和B表结构相同，如何同步数据？

SELECT dbfb
PACK
select dbfA
DELETE FROM dbfA WHERE nid in (select nid FROM dbfB)
PACK
append from dbfB

Close Databases
Create Cursor t1 (id I, data1 C(10), data2 C(10))
Insert into t1 (id, data1, data2) Values (1, 'a', 'aaa')
Insert into t1 (id, data1, data2) Values (2, 'b', 'bbb')
Insert into t1 (id, data1, data2) Values (3, 'c', 'ccc')
Insert into t1 (id, data1, data2) Values (4, 'd', 'ddd')
Create Cursor t2 (id I, data1 C(10), data2 C(10))
Insert into t2 (id, data1, data2) Values (1, 'aa', 'aaa')        && data1 不同
Insert into t2 (id, data1, data2) Values (2, 'b', 'bbb')
Insert into t2 (id, data1, data2) Values (3, 'c', 'ccccc')        && data2 不同
Insert into t2 (id, data1, data2) Values (5, 'e', 'eee')        && 新增记录

*-- 提取 t2 中与 t1 不同的记录（不包括 t2 新增的）
Select t2.* from t2 where exists ( ;
    Select a.* from ( ;
        Select id, Cast(Sys(2017,'',-1,1) as C(10)) as crc from t2) a ;
    inner join ( ;
        Select id, Cast(Sys(2017,'',-1,1) as C(10)) as crc from t1) b on a.id = b.id ;
    where a.id = t2.id  and a.crc != b.crc ;
)