Count of order number

Question

Hi,
How to get list of year and count of orders_number from a table?
Year       Count
2000        100
2001        150
2002        0
2003        212even though there is no data in table for year 2002, it should display 2002 with 0 count
where to_char(order_year,'YYYY) between 2000 and 2003Thanks
Sandy

Answer 1

I think you need to create a table that holds all the years that you want to count upon. Then you can join your orders table with that "yearlist" table. This "yearlist" table can be a virtual table that is created on the fly useing some different approaches.
example startyear=2000, endyear= 2005
/* using hierarical select with connect by */
with yearlist as (select 2000+level-1 as yr
              from dual
              connect by level <= 2005-2000+1)
select * from yearlist;
YR
2000
2001
2002
2003
2004
2005
/* using a dummy table that has enough rows */
with yearlist as (select 2000+rownum-1 as yr
            from all_objects 
            where rownum <= 2005-2000+1
            order by yr)
select * from yearlist
YR
2000
2001
2002
2003
2004
2005adding your orders table should give someting like this
untested
with yearlist as (select 2000+rownum-1 as yr, to_date('01.01.'||to_char(2000+rownum-1,'fm0000'),'DD.MM.YYYY') as yrDate
            from all_objects 
            where rownum <= 2005-2000+1
            order by yr)
select y.yr , count(*), count(distinct o.order_number)
from yearlist y
left join orders o on trunc(o.order_date,'year') = y.yrDate
group by y.yr
order by y.yrEdited by: Sven W. on Aug 25, 2010 6:49 PM - added example using the orders table