SELECT DECODE(GG,'',0,GG),DECODE(HH,'',0,HH) FROM (SELECT 1 GG FROM DUAL WHERE 1=2 )A, (SELECT 2 HH FROM DUAL) B上面语句因为A表没有满足条件的行而出现什么都查询不到的情况,
而我的目的是想查出这样一个结果: 0 , 2
而我的目的是想查出这样一个结果: 0 , 2
(SELECT
case when count(*)=0 then '' else '1' end GG
FROM DUAL where 1=2)A,
(
SELECT
case when count(*)=0 then '' else '2' end HH
FROM DUAL
)B
on a.hh=b.gg
FROM (SELECT 1 GG FROM DUAL WHERE 1=2 )A
, (SELECT 2 HH FROM DUAL) B
where a.gg(+)=b.hh