How can i implement this query in sql server? - sql-server

Question

I'm beginner in sql server,have two table ,table GetOnlineBills with this shape:
--Telno-- --Cycle-- --Bill--
nchar(20) nchar(20) float
And table 25Percantage:
--Telno-- --Cycle-- --Bill--
nchar(20) nchar(20) float
want to write query or tsql for analysis Telno in GetOnlineBill table with this flow:
1-fetch Telno ang get it bill value in Cycle 951 and Cycle 952
2-If Bill(952)>Bill(951) then write into 25 percantage this data (Bill(952)-Bill(951))
into GetOnlineBill's table write subscribe Bill information per cycle,For example have two subscribe(in really world have 1 million subscribe) with this plan:
into the GetOnlineBills one mounth data is this:
--Telno-- --Cycle-- --Bill--
12345 951 300
54321 951 500
and other month data is :
--Telno-- --Cycle-- --Bill--
12345 952 400
54321 952 600
and final GetOnlineBill for two mounth is:
--Telno-- --Cycle-- --Bill--
12345 951 300
54321 951 500
12345 952 400
54321 952 600
Now,i want analysis GetOnlineBill,want write query or tsql to create final 25Percantage table show me this:
--Telno-- --Cycle-- --Bill--
12345 951-952 100 ------>Bill(952)-Bill(951) Minus
54321 951-952 300
----------------------------------------
Explain:
Bill:Field Name on GetOnlineBill table
952:Cycle
951:Cycle
How can i write query or tsql for that purpose?please write and post me.thanks all.

Answer 1

Inner join should help you:
SELECT y.Telno,
t.Cycle+'-'+y.Cycle Cycle,
y.Bill - t.Bill Price
FROM YourTable y
INNER JOIN YourTable t
ON y.Telno = t.TelNo AND CAST(y.Cycle as int)-1 = CAST(t.Cycle as int)
Output:
Telno Cycle Price
12345 951-952 100
54321 951-952 100
If Cycle column can not be converted to integer then you need some other field to order table right way and do join with that field (or OUTER APPLY)

Answer 2

Try as the below:
DECLARE #Tbl TABLE (TelNo NCHAR(20), Cycle NCHAR(20), Bill FLOAT)
INSERT INTO #Tbl
VALUES
('12345', '951', 300),
('12345', '952', 400),
('54321', '951', 500),
('54321', '952', 600)
;WITH CTE
AS
(
SELECT *, DENSE_RANK() OVER (ORDER BY Cycle) MonthId
FROM #Tbl
)
SELECT
CurrentMonth.TelNo,
CurrentMonth.Cycle + '-' + NextMonth.Cycle Cycle,
CASE
WHEN NextMonth.Bill > CurrentMonth.Bill THEN NextMonth.Bill - CurrentMonth.Bill
ELSE CurrentMonth.Bill END Bill -- Change as you want
FROM
CTE CurrentMonth LEFT JOIN
CTE NextMonth ON CurrentMonth.TelNo = NextMonth.TelNo AND (NextMonth.MonthId - 1) = CurrentMonth.MonthId
WHERE
NextMonth.MonthId IS NOT NULL
Result:
TelNo Cycle Bill
-------------------- ------------------------ ---------
54321 951-952 100
12345 951-952 100