Complex query with multiple conditions - sql

Question

The 'complex'-part of the title might be subjective, but for me, it is rather complex.
I have a table called Contracts (C) and FinancialYears (FY). A contract will have multiple financial years (one per year), created automatically, if a specific status is met (for example, cancelled contracts won't get new financial year records, but approved contracts will). It's the FY that is having a specific status each years. For example:
--------------------FinancialYears-------------------
ContractID: 1 | 1 | 1
StatusID: 2 | 3 | 5
dStart: 01-01-2012 | 01-01-2013 | 01-01-2014
dEnd: 31-12-2012 | 31-12-2013 | 31-12-2014
Year: 2012 | 2013 | 2014
-----------------------------------------------------
(For example: StatusID (2, 3, 5), (Proposed, Approved, Cancelled))
Now assume a user wants to find out how many contracts are approved at this point of time, then the query should be looking at the most recent financial year of the contract, and that's what I'm having a hard time with.
I have to write a query that does the following:
SELECT *
FROM Contracts C
INNER JOIN FinancialYears FY ON FY.ContractID = C.ContractID
WHERE StatusID = X AND (dStart < GETDATE() AND dEnd > GETDATE())
// This would search on the financial year of the contract which has its valid
period in-between today.
But since a, for example, cancelled contract will not have a new financial year in the next year, I would never be able to query today on a cancelled contract of 2014, so I need to adjust the following condition to the query somehow:
// IF (dStart < GETDATE() AND dEnd > GETDATE()) RETURNS 0, THEN DO INSTEAD:
SELECT TOP 1
//
WHERE (dEnd < GETDATE)
ORDER BY ENDDATE DESC
// With other words: if there is no ongoing financial year between the given time interval,
then select the most recent financial year in the past.
Could anyone help me out here?
Thank you.

Answer 1

Here's a quick mock-up:
SELECT *
FROM Contracts C
cross apply (
select top 1 ContractID
from FinancialYears where dStart < GETDATE()
order by dEnd desc
) F on C.ConractID = F.ContractID
But you'll probably need some extra criteria to find all of the Contracts, for example customer code or something.

Answer 2

You just need to filter the contracts where the current date falls between the start and end date of contracts that are approved if I'm not mistaken.
Here's a demo SQL Fiddle
MS SQL Server Schema Setup:
CREATE TABLE FinancialYearContracts
([ContractID] int, [StatusID] int, [dStart] datetime, [dEnd] datetime, [Year] int)
;
INSERT INTO FinancialYearContracts
([ContractID], [StatusID], [dStart], [dEnd], [Year])
VALUES
(1, 2, '2012-01-01 00:00:00', '2012-12-31 00:00:00', 2012),
(1, 3, '2013-01-01 00:00:00', '2013-12-31 00:00:00', 2013),
(1, 5, '2014-01-01 00:00:00', '2014-12-31 00:00:00', 2014),
(2, 2, '2013-01-01 00:00:00', '2013-12-31 00:00:00', 2013),
(2, 3, '2014-01-01 00:00:00', '2014-12-31 00:00:00', 2014),
(2, 3, '2015-01-01 00:00:00', '2015-12-31 00:00:00', 2015),
(3, 2, '2014-01-01 00:00:00', '2014-12-31 00:00:00', 2014),
(3, 3, '2015-01-01 00:00:00', '2015-12-31 00:00:00', 2015),
(4, 2, '2014-01-01 00:00:00', '2014-12-31 00:00:00', 2014),
(5, 2, '2013-01-01 00:00:00', '2013-12-31 00:00:00', 2013),
(5, 3, '2014-01-01 00:00:00', '2014-12-31 00:00:00', 2014),
(5, 3, '2015-01-01 00:00:00', '2015-12-31 00:00:00', 2015),
(6, 2, '2013-01-01 00:00:00', '2013-12-31 00:00:00', 2012),
(6, 3, '2014-01-01 00:00:00', '2014-12-31 00:00:00', 2013),
(6, 5, '2015-01-01 00:00:00', '2015-12-31 00:00:00', 2014)
;
Query to generate results:
declare #DateFilter as datetime = GETDATE()
declare #Status as int = 3
SELECT *
FROM FinancialYearContracts
WHERE #DateFilter BETWEEN dStart AND dEnd AND StatusID = #Status
Results:
| CONTRACTID | STATUSID | DSTART | DEND | YEAR |
|------------|----------|--------------------------------|---------------------------------|------|
| 2 | 3 | January, 01 2015 00:00:00+0000 | December, 31 2015 00:00:00+0000 | 2015 |
| 3 | 3 | January, 01 2015 00:00:00+0000 | December, 31 2015 00:00:00+0000 | 2015 |
| 5 | 3 | January, 01 2015 00:00:00+0000 | December, 31 2015 00:00:00+0000 | 2015 |
This shows contracts that are currently in the approved status based on the sample data I put together.