Cross Calculation in SQL Server - php

Question

I have a complicated request. I have to make a report in PHP like the picture below.
Part summarized yield must be filled with across calculation.
Like I explain in formula column, value in part summarized yield got from calculation between location yield and part summarized yield.
(See this formula)
How to do that calculation in a PHP report?
I already tried using a cursor, but it still did not work.
Here is my cursor calculation:
--In PHP file, i make query to insert data first to table tyield_summary
--Cursor to input yield_summary
Declare #nourut varchar(2), #maxnourut varchar(2), #bpnum varchar(20), #pnum varchar(20), #curnourut varchar(2), #psum decimal(18,2), #ysum decimal(18,2)
DECLARE StockCursor CURSOR
FOR
select no_urut, part_number, Part_Summary
from tyield_summary
where no_urut<>'99'
order by part_number desc, no_urut asc
set #bpnum=''
OPEN StockCursor
FETCH NEXT FROM StockCursor INTO #nourut, #pnum, #psum
WHILE ##FETCH_STATUS=0
BEGIN
if #bpnum=#pnum
begin
select top 1 #curnourut=no_urut
from tyield_summary
where part_number=#pnum
and no_urut<#nourut
order by no_urut desc
set #bpnum=#pnum
select #maxnourut = max(no_urut) from tyield_summary
where part_number=#pnum
update tyield_summary
set yield_summary = case when Part_Summary=0 then #psum else (Part_Summary*#psum)/100 end
where part_number=#pnum
and no_urut=#curnourut
end
else
begin
set #bpnum=#pnum
end
FETCH NEXT FROM StockCursor INTO #nourut, #pnum, #psum
END
CLOSE StockCursor
DEALLOCATE StockCursor
Here table structure :
I need to fill part_summary field using formula that i show in excel.
In formula show, calculation using cross field.

Answer 1

Here is how you can do it (without nasty cursors).
Just use row number over your ordering/aggregation criteria to find the next row,
left join each row with its next (not forgetting the aggregation criteria) and it's done.
Let's use an example (and here is how you properlu post a table structure):
create table Lazydude
(
Partno varchar(20) not null
,Seq int not null
,[Value] float not null
)
GO
insert into Lazydude (Partno, Seq, [Value])
values
('AAA', 1, 77.7)
,('BBB', 0, 2)
,('BBB', 3, 3)
,('BBB', 9, 5)
,('CCC', 1, 33.3)
,('CCC', 2, 33.3)
GO
and to select using row number and use the result in a self-join
with Temp as(
select Partno, Seq, [Value]
,ROW_NUMBER() OVER(ORDER BY Partno, Seq) AS [Row]
from Lazydude
)
select t0.Partno, t0.Seq, t0.[Value], t0.[Row]
, t1.row as [Next Row], t1.[Value] as [Next Value]
, case when t1.row is null
then t0.[Value]
else t0.Value * t1.Value
end as [The Calculation]
from Temp t0
left join Temp t1 on t1.[Row] = t0.[Row] + 1 and t1.Partno = t0.Partno
You can see the results in the SQL Fiddle
Partno Seq Value Row Next Row Next Value The Calculation
AAA 1 77.7 1 (null) (null) 77.7
BBB 0 2 2 3 3 6
BBB 3 3 3 4 5 15
BBB 9 5 4 (null) (null) 5
CCC 1 33.3 5 6 33.3 1108.8899999999999
CCC 2 33.3 6 (null) (null) 33.3