ETL-拉链算法-带删除的拉链算法

truncate table CUST;truncate table TAG_CUST;
truncate table vt_inc;truncate table vt_new;
insert into CUST values(100,\'张三\',\'13333333333\');
insert into CUST values(200,\'李四\',\'12222222222\');
insert into CUST values(300,\'王五\',\'15555555555\');
insert into vt_new
    select CUST_ID,CUST_NAME,PHONE_NUM,\'20160101\',\'29991231\' from CUST;
insert into vt_inc
    select a.* from vt_new a
        left join TAG_CUST b on a.CUST_ID=B.CUST_ID and b.ETL_END_DT=\'29991231\'
        where b.CUST_ID is null or a.PHONE_NUM<>b.PHONE_NUM;
insert into vt_inc
    select b.CUST_ID,a.CUST_NAME,a.PHONE_NUM,a.ETL_START_DT,\'19990101\' from vt_new a
        right join TAG_CUST b
            on a.CUST_ID=b.CUST_ID
             where a.CUST_ID is null and b.ETL_END_DT=\'29991231\';
update TAG_CUST a set ETL_END_DT=\'20160102\'
    where ETL_END_DT=\'29991231\' and exists
    (select 1 from vt_inc b
     where a.CUST_ID=b.CUST_ID);
insert into TAG_CUST
    select a.* from vt_inc a where a.ETL_END_DT=\'29991231\';