select *
from(
select TO_CHAR(KAG712AA,'0000')
,TO_CHAR(KAG712AB,'00')
,TO_CHAR(KAG712AC,'00')
,TO_CHAR(KAG712AA,'0000') || '/' || TO_CHAR(KAG712AB,'00') || '/' || TO_CHAR(KAG712AC,'00') as dlDt
from txzz_skag70
)
where dlDt >= '2008/10/01' 不加最外层的条件是有值得,而且现实的结果中也确实有满足外层条件的值
但是把外层条件加上的时候就什么也检索不出来了
请问哪里写的不对吗?因为这几个字段有可能为空值,所以避免用TO_DATE出错才改用的字符比较
from(
select TO_CHAR(KAG712AA,'0000')
,TO_CHAR(KAG712AB,'00')
,TO_CHAR(KAG712AC,'00')
,TO_CHAR(KAG712AA,'0000') || '/' || TO_CHAR(KAG712AB,'00') || '/' || TO_CHAR(KAG712AC,'00') as dlDt
from txzz_skag70
)
where dlDt >= '2008/10/01' 不加最外层的条件是有值得,而且现实的结果中也确实有满足外层条件的值
但是把外层条件加上的时候就什么也检索不出来了
请问哪里写的不对吗?因为这几个字段有可能为空值,所以避免用TO_DATE出错才改用的字符比较
from(
select TO_CHAR(KAG712AA,'0000')
,TO_CHAR(KAG712AB,'00')
,TO_CHAR(KAG712AC,'00')
,TO_CHAR(KAG712AA,'0000') || '/' || TO_CHAR(KAG712AB,'00') || '/' || TO_CHAR(KAG712AC,'00') as dlDt
from txzz_skag70
)
where to_char(dlDt,'YYYY/MM/DD') >= '2008/10/01'