Stored Procedure/Function Logic for Summing of account balances - sql

Question

Version B C D output Account number Balance
----------------------------------------------------------------
2 1283 1303 0 4071 1 10
2 1283 1304 0 4072 2 20
3 1283 4068 1303 4071 1 30
3 1283 4069 1304 4072 4 40
4 1283 4071 4068 4071 5 -50
4 1283 4072 4069 4072 2 90
Version,B,C,D are columns present in all_details table.Column "Output" is the desired output i wish to achieve and i wish to store all the above columns in a table until output
How in the first line of Output i placed 4071 is
1) i took 1303 in column C and then looked into column D
2) then it is again referring to 4068 in column C
3) Then i took 4068 and it is refering to 4071 in column C its like a linkage
I'm using column B as it is related information to other columns.
i need a another column output so that i can identify related links and sum up balances.For example
I'll sum up related links 1303,4068,4071 balances Group by Output i'll get 10+40 = 50 for account 1 and -50 for account 5 corresponding to 4071

Answer 1

So from what I am understanding, you need to have something that recursively finds the last linked number, for a given number. These links exists between your Column C and Column D.
I am assuming that Column B is a grouping type number, but I am certain that you might be able to figure out how to adjust the function to return what you need it to return.
What you will need to do is build a SQL function that will iterate through your table and follow the links until it can find no more links. Details and example follow below as to how one can do that.
So firstly the building up of the sample data, as you presented them (NOTE this creates a table on your database, be careful!)
-- Building testing data
if exists (select 1
from sys.objects
where name = 'versionhistory'
and type = 'U')
begin
drop table versionhistory
end
create table versionhistory
( versionno int,
colB int,
colC int, -- Current Value
colD int ) -- Previous value
insert versionhistory
( versionno,
colB,
colC,
colD )
values -- B C D
( 2, 1283, 1303, 0),
( 2, 1283, 1304, 0),
( 3, 1283, 4068, 1303),
( 3, 1283, 4069, 1304),
( 4, 1283, 4071, 4068),
( 4, 1283, 4072, 4069)
go
Now we need to create the function that will iterate through the tables records, follow the links between the two columns until it can find no more links, then return the last linked value.
-- Create the function that will get the last entry for a give number
if exists (select 1 from sys.objects where name = 'f_get_last_ver' and type = 'FN')
begin
drop function f_get_last_ver
end
go
create function f_get_last_ver
( #colB int,
#colC int )
returns int
as
begin
declare #nextColC int,
#lastColC int
-- Initial check if there is a 'next' version
select #nextColC = isnull((select vh.colC
from versionhistory vh
where vh.colB = #colB
and vh.colD = #colC), 0)
-- This will handle the loop until there are no more entries linked
while isnull(#nextColC, 0) <> 0
begin
-- Store our last value for return purposes
select #lastColC = #nextColC
-- Get our next version number that is linked
select #nextColC = isnull((select vh.colC
from versionhistory vh
where vh.colB = #colB
and vh.colD = #nextColC), 0)
end
-- Return our last value, otherwise if no linkage was found, return the input
return isnull(#lastColC, #colC)
end
go
And finally here you have the usage of the function.
-- Example usage
select dbo.f_get_last_ver(1283, 1303), -- returns 4071
dbo.f_get_last_ver(1283, 1304) -- returns 4072
Remember to clean up your database when done testing/experimenting with this
I hope that the comments inside the function will explain enough of what is happening, but if something is unclear, ask away.
P.S. Please rename your columns and variables in your actual code into more meaningful column names and variables, since B, C, D doesn't really explain what they are used for.