如何显示不同的日期数据（来自同一表）作为Oracle中的列

Question

I'm sorry if the title wasn't too clear, but the following explanation will be more accurate.

I have the following view:

DATE          USER         CONDITION
20140101      1            A
20140101      2            B
20140101      3            C
20140108      1            C
20140108      3            B
20140108      2            C

What I need to do is present how many users where in all conditions this week and 7 days before today.

Output should be like this:

Condition          Today          Last_Week (Today-7)
A                  0              1
B                  1              1
C                  2              1

How can I do this in Oracle? I will need to do this for 4 weeks so itll be Today-7,14-21.

I've tried this with group by but I get the "week2" as rows. Then I've tried something like Select conditions, (select count(users) from MyView where DATE='Today') FROM MyView (looking at something thats actually working) but it doesnt work for me.

Achieved this with a little modification of the accepted answer:

select condition, 
   count(case when to_date(xdate) = to_date(sysdate) then 1 end) to_day,
   count(case when to_date(xdate) = to_date(sysdate-7) then 1 end) last_7_days
from my_table
group by condition

Answer 1

select condition, count(case when to_date(xdate) = to_date(sysdate) then 1 end) to_day,
       count(case when to_date(xdate) < to_date(sysdate) then 1 end) last_7_days
  from my_table
 where to_date(xdate) >= to_date(sysdate) - 7
 group by condition

Answer 2

select condition
,      sum
       ( case
         when date between trunc(sysdate) - 7 and trunc(sysdate) - 1
         then 1
         else 0
         end
       )
       last_week
,      sum
       ( case
         when date between trunc(sysdate) and trunc(sysdate + 1)
         then 1
         else 0
         end
       )
       this_week
from   table
group
by     condition

By using the conditional count (as a sum) and grouping on condition you can filter out all desired dates. Note that using trunc will cause to use the begin of the day.