关于子查询别名的问题
数据
--------------------------------(数据A中FLDCPH是没有数据的就是空)
ID FLDCPH STARTTIME
A 2015-11-06 15:42:52
B OXA 2015-11-05 11:26:30
---------------------------------
查询语句
select * from T1 a where exists (select 1 from T1 where fldcph=fldcph and TO_CHAR(a.starttime, 'YYYY-MM-DD HH24:MI')>'2015-11-04 13:47:00')
结果
--------------------------------
ID FLDCPH STARTTIME
A 2015-11-06 15:42:52
B OXA 2015-11-05 11:26:30
---------------------------------
查询语句
select * from T1 a where exists (select 1 from T1 where fldcph=a.fldcph and TO_CHAR(a.starttime, 'YYYY-MM-DD HH24:MI')>'2015-11-04 13:47:00')
结果
--------------------------------
ID FLDCPH STARTTIME
B OXA 2015-11-05 11:26:30
---------------------------------
加了别名和不加别名查询知道意思是不一样,但是不知道是什么道理