Crystal reports, selecting latest apearence of group in table - sql-server

Question

I am new in this Crystal Reports thing and I have problem, since my coworker usually doing this stuff is sick at home I need to figure it out my self. I have 2 tables.
First is like this:
Article.ID Article.name Article.buyingprice
1 aa 2.00
2 bb 1.00
3 cc 3.50
4 dd 4.20
5 ee 2.00
And second is like this:
Income.ID Income.article Income.date Income.number Income.quantity
1 2 79100 P1 2.00
2 1 79100 P1 3.00
3 4 79101 P2 2.00
4 3 79101 P2 1.00
5 1 79101 P2 4.00
6 5 79101 P2 1.00
7 2 79103 P3 15.00
What I need is formula for selecting Income.quantity from the latest Income document. For example for article aa it will be 4.00 and for article bb it will be 15. Please save my job folks :)
Report is grouped by article.name.

Answer 1

For your solution you can make a group in Crystal report
Add group on ArticleId sort by ascending
Add One more group on IncomeId sort by descending
Now Suppress all Group headers and footer
open section expert , set formula below
Formula: if(previous({Command.Aritcle.ID}) = {Command.Aritcle.ID}) then true else false;

Answer 2

This Can Be Achieved in SQl server by using CTE
BEGIN TRAN
CREATE TABLE #Article (ID INT ,name NVARCHAR(20),buyingprice Decimal (15,2))
CREATE TABLE #Income (ID INT ,article INT,DATE nvarchar(50),number nvarchar(20),quantity Decimal (15,2))
insert into #Article
SELECT 1,'aa',2.00 union all
SELECT 2,'bb',1.00 union all
SELECT 3,'cc',3.50 union all
SELECT 4,'dd',4.20 union all
SELECT 5,'ee',2.00
insert into #Income
select 1,2,'79100','P1',2.00 union all
select 2,1,'79100','P1' ,3.00 union all
select 3,4,'79101','P2',2.00 union all
select 4,3,'79101','P2',1.00 union all
select 5,1,'79101','P2',4.00 union all
select 6,5,'79101','P2',1.00 union all
select 7,2,'79103','P3',15.00
go
with CTE as
( select A.ID,name,b.date, B.quantity,ROW_NUMBER() OVER(PARTITION BY a.ID,name ORDER BY a.ID,name ) AS Rn
FROM #Article A inner JOIN #Income B ON A.ID=B.article
)
SELECT a.ID,a.date,a.name, a.quantity
FROM CTE a
WHERE a.Rn= (SELECT MAX(rn) FROM cte b)
ROLLBACK TRAN