Get Percentages by Department

Question

Hi All. I have a query that brings in spend sum($$) data for all departments, say within Cosmetics for customers, this works, but I wanted to see their percentage cross-over spend again say Department 215, I am not sure how to do the best way (the most efficient-correct way), would appreciate some help!
Using Oracle 10G, Here is what I currently have:
I only want to see customer who spent > $0 in the last 12 months.
select d.DEPT_NUMBER, sum (a.SPEND_12_MO) SUM_12_MO
from a.DEPT_SPEND a, USER_VIEW b, DEPARTMENT_CLASS d
where a.skey=b.skey
and a.DEPT_NUMBER = d.DEPT_NUMBER
and b.STORE_NUM is not null
and d.DEPT_NUMBER IN (1,2,3,4,5,blablalba,alldepts)
group by d.DEPT_NUMBER;
Then maybe I can have another query that will Query #1 that would do the percentage cross-shopping against say Dept 215.
So if in Query #1, I enter 20 departments, in Query #2 the result would give me an overall percentage cross-overs of 215 to the 20 depertments ? based on spend sum($$) ?
Thank you!

Answer 1

Hi,
No doubt you have a ckear idea if what you want. To those of us who have not been working with your tables or this particular problem for a long time, it is a riddle, wrapped in a mystery, inside an enigma.
Whenever you have a question, it helps to post:
(1) The version of Oracle (and any other relevant software) you're using (You did this.)
(2) A little sample data (just enough to show what the problem is) from all the relevant tables
(3) The results you want from that data
(4) Your best attempt so far (formatted) (You posted this, but since it's unformated, it's very hard to read.)
Executable SQL statements (like "CREATE TABLE AS ..." or "INSERT ..." statements) are best for (2).
If you can present your problem using commonly available tables (for example, tables in scott schema, or views in the data dictionary), then you can omit (2).
Formatted tabular output is okay for (3). Type these 6 characters:
{code}
(small letters only, inside curly brackets) before and after formatted text, to preserve spacing.
Simplify the problem if you can. For example, if your real query involves 20 depatments, post a problem with only 3 or 4.
It looks like you were on the right track with the analytic SUM function and CASE, but I really don't understand the problem well enough to say.