关于这条sql的问题
请问下 这2条sql 为什么一个可以查出结果 一个 查出的结果为空 谢谢
SELECT a.Staffno,
SUM(a.Totalcount)
FROM t_Daylog_CallCause a,
t_RptTmp_FirstCallCause b
WHERE a.logdate >= to_date('2008-11-27','yyyy-mm-dd')
AND a.logdate < to_date('2008-11-28 ','yyyy-mm-dd')
and a.callcauseid<>-1
and a.staffno like '10%'
AND a.CallCauseId LIKE b.Id||'%'
AND b.UserName='icd'
GROUP BY a.StaffNo;
-------------------------
SELECT a.Staffno,
SUM(a.Totalcount)
FROM t_Daylog_CallCause a,
t_RptTmp_FirstCallCause b
WHERE a.logdate >= to_date('2008-11-27 18:00:00','yyyy-mm-dd hh24:mi:ss')
AND a.logdate < to_date('2008-11-28 18:00:00','yyyy-mm-dd hh24:mi:ss')
and a.callcauseid<>-1
and a.staffno like '10%'
AND a.CallCauseId LIKE b.Id||'%'
AND b.UserName='icd'
GROUP BY a.StaffNo;
数据库版本 oracle 9i