偏移量函数进阶一oracle空行取上一行

create table test_IGNORE as
select '商业银行' as rclass,'招商银行' as bank , 1 as id from dual 
union all 
select '','浦发银行' , 2 as id from dual 
union all 
select '','中信银行' , 3 as id from dual 
union all 
select '','广发银行' , 4 as id from dual 
union all 
select '','光大银行' , 5 as id from dual 
union all 
select '','平安银行' , 6 as id from dual

SELECT NVL(T.RCLASS,LAG(T.RCLASS, 1) OVER(ORDER BY T.ID)) AS RCLASS,
       T.BANK,
       T.ID
FROM TEST_IGNORE T;

SELECT NVL(T.RCLASS,LAG(T.RCLASS IGNORE NULLS, 1) OVER(ORDER BY T.ID)) RCLASS,
       T.BANK,
       T.ID
FROM TEST_IGNORE T;