Count with date rollover

Question

I was wondering how this can be achieved:
I need to do a count of applications by application_type where the "application_recieved_date" >= JAN-2010.
The only issue is that not all applications have a "application_recieved_date", soem are NULL. So i need some sort of rollover date, if this doesnt exist then use another date on the application (application_recieved_date for example), then if this doesnt exist then use another date.
Any help would be great, i have trying decodes and nvl2 functions, but nothing yet.
below is basic query just so you can see names e.t.c, but i really cannot workout the best way of solving this
select application_type, count(*)                   
            from pple_t_application
           group by application_type
           order by application_type;

Answer 1

Hi,
Use COALESCE:
COALESCE (dt1, dt2, dt3, dt4)COALESCE takes 2 or more arguments of the same datatype, and returns the first argument that is not NULL.
I hope this answers your question.
If not, post a little sample data (CREATE TABLE and INSERT statements, relevant columns only), and the results you want from that data.
Explain how you get those results from that data.
Always say what version of Oracle you're using.