SQL oracle with joining tables and Max functions - sql

Question

Some help please? Just a noob here starting to learn how to write SQL and ran into this problem. I know how to use the MAX function but I can't figure out how to join all these requirements together. I have two tables, Accounts and Books (below is an example of the data)
Accounts
ID Series YesorNot Dated Filed Plan Year
1 123 Yes 06/12/2015 2015
2 123 No 06/12/2015 2015
3 145 Yes 06/06/2015 2015
4 145 No 02/02/2015 2014
5 198 Yes 02/03/2015 2015
6 187 Yes 02/14/2013 2013
7 153 Yes 01/02/2011 2011
Books
Primary Key Date Created ID
1 06/13/2015 123
2 06/12/2015 123
3 06/07/2015 145
4 02/02/2015 145
5 02/03/2015 198
Two tables: Accounts and Books
Looking for:
1. Data that exists in both tables by the Project ID = Primary Key
2. I only want one unqiue Series (Series also = ID)
3. I want the MAX (most recent) value of Plan Year, and then if there are duplicates for Plan Year, I need the MAX (most recent) value of Date Created.
4. I just need the columns Project ID, Series, YesorNot, Date Filed, Plan Year so my output should be like this:
Project ID Series YesorNot Dated Filed Plan Year
1 123 Yes 06/12/2015 2015
3 145 Yes 06/06/2015 2015
4 145 No 02/02/2015 2014
5 198 Yes 02/03/2015 2015

Answer 1

First join the tables:
SELECT B.Primary_Key as Project_ID, A.Series, A.YesorNot, A.Date_Filed, A.Plan_Year
FROM Books B
JOIN Accounts A ON B.ID = A.Series
You should have been able to get this far on your own (and you should have posted it as part of the question) -- if you can't I'd say find a different career. Assuming you could now the slightly harder part.
Now we add a row number based on your criteria
ROW_NUMBER() PARTITION BY (B.Primary_Key, A.Series, A.YesorNot, A.Date_Filed ORDER BY A.Date_Year DESC, B.Date_Created DESC) AS RN
Now just take the first of the row number.
SELECT Project_ID, Series, YesorNot, Date_Filed, Plan_Year
FROM (
SELECT B.Primary_Key as Project_ID, A.Series, A.YesorNot, A.Date_Filed, A.Plan_Year,
ROW_NUMBER() PARTITION BY (B.Primary_Key, A.Series, A.YesorNot, A.Date_Filed ORDER BY A.Date_Year DESC, B.Date_Created DESC) AS RN
FROM Books B
JOIN Accounts A ON B.ID = A.Series
) X
WHERE RN = 1