alter session set nls_date_format='mm/dd/yyyy hh24:mi:ss'; 然后再试试a.rq=b.rq
依题所示 a 表肯定为DATE型了,而b表不能肯定是date型。 try: where .... and to_char(a,'yyyymmdd') = to_char(to_date('01/23/2005 00:00:00','mm/dd/yyyy HH24:mi:ss'),'yyyymmdd')test: select to_char(to_date('01/23/2005 00:00:00','mm/dd/yyyy HH24:mi:ss'),'yyyymmdd') from dual ------------------------------- 如两个字段全是DATE型的: where .... and to_char(a,'yyyymmdd') = to_char(b,'yyyymmdd')
依题所示 a 表肯定为DATE型了,而b表不能肯定是date型。 try: where .... and to_char(a,'yyyymmdd') = to_char(to_date('01/23/2005 00:00:00','mm/dd/yyyy HH24:mi:ss'),'yyyymmdd')test: select to_char(to_date('01/23/2005 00:00:00','mm/dd/yyyy HH24:mi:ss'),'yyyymmdd') from dual ------------------------------- 如两个字段全是DATE型的: where .... and to_char(a,'yyyymmdd') = to_char(b,'yyyymmdd')
a.rq?b.rq是什么用法?
desc a
desc b
看看两个日期字段,确实是日期型吗
然后再试试a.rq=b.rq
try:
where ....
and to_char(a,'yyyymmdd') = to_char(to_date('01/23/2005 00:00:00','mm/dd/yyyy HH24:mi:ss'),'yyyymmdd')test:
select to_char(to_date('01/23/2005 00:00:00','mm/dd/yyyy HH24:mi:ss'),'yyyymmdd') from dual
-------------------------------
如两个字段全是DATE型的:
where ....
and to_char(a,'yyyymmdd') = to_char(b,'yyyymmdd')
try:
where ....
and to_char(a,'yyyymmdd') = to_char(to_date('01/23/2005 00:00:00','mm/dd/yyyy HH24:mi:ss'),'yyyymmdd')test:
select to_char(to_date('01/23/2005 00:00:00','mm/dd/yyyy HH24:mi:ss'),'yyyymmdd') from dual
-------------------------------
如两个字段全是DATE型的:
where ....
and to_char(a,'yyyymmdd') = to_char(b,'yyyymmdd')