表记录序数的添加问题
有表T1:
a b c d  
1001 blue 20080303 7:55
1001 blue 20080303 12:06
1001 blue 20080303 13:25
1001 blue 20080303 17:36
1001 blue 20080304 7:50
1001 blue 20080304 12:10
1001 blue 20080304 13:22
1001 blue 20080304 17:35

如何实现表T2:
a b c d e  
1001 blue 20080303 7:55 1
1001 blue 20080303 12:06 2
1001 blue 20080303 13:25 3
1001 blue 20080303 17:36 4
1001 blue 20080304 7:50 1
1001 blue 20080304 12:10 2
1001 blue 20080304 13:22 3
1001 blue 20080304 17:35 4

------解决方案--------------------
select *,=(select count(*) from tb where a.c=c and d<a.d)+1
from tb a
------解决方案--------------------
select *,e =(select count(*) from tb where a.c=c and d <a.d)+1 
from tb a
------解决方案--------------------

SQL code

select * , e = (select count(1) from t1 where a = t.a and b = t.b and c = t.c and d < t.d) + 1 from t1