我想取出 a,b中birthday相同的记录.是同年,还是同年同日,还是同年同月同时,还是同年同月同日,还是同年同月同日同时,还是同年同月同日同时同分,还是同年同月同日同时同分同秒? 按歌德巴赫猜想,一般应该是同年同月同日。select a.username,a.sex,a.birthday,b.studentname,b.studentId from a,b where to_char(a.birthday,'yyyy-mm-dd')=to_char(b.birthday,'yyyy-mm-dd');
select a.username,a.sex,a.birthday,b.studentname,b.studentId from a,b where to_char(a.birthday,'yyyy-mm-dd HH24:MI:SS')=to_char(b.birthday,'yyyy-mm-dd HH24:MI:SS');
按歌德巴赫猜想,一般应该是同年同月同日。select a.username,a.sex,a.birthday,b.studentname,b.studentId from a,b
where to_char(a.birthday,'yyyy-mm-dd')=to_char(b.birthday,'yyyy-mm-dd');
如果你不等于是指年月日时分秒不等,那么直接a.birthday != b.birthday
如果你只是想比较年月日,则turnc(a.birthday) != turnc(b.birthday)
select a.username,a.sex,a.birthday,b.studentname,b.studentId from a,b
where to_char(a.birthday,'yyyy-mm-dd HH24:MI:SS')=to_char(b.birthday,'yyyy-mm-dd HH24:MI:SS');
直接a.birthday != b.birthday啊
如果要=匹配,也可以直接a.birthday = b.birthday