How to check a SQL CASE with multiple conditions? - sql

Question

I have two tables. Accounts ACC and FinancialTrans FT
The FinancialTrans table is as follows:
AcctID TransTypeCode DateOfTrans
123 TOLL 2016-06-06 00:00:00.000
123 TOLL 2016-06-02 00:00:00.000
123 TOLL 2016-04-28 00:00:00.000
123 PYMT 2016-03-11 00:00:00.000
123 TOLL 2015-12-22 00:00:00.000
123 TOLL 2015-12-22 00:00:00.000
The requirement is:
When any Accounts have NO 'TOLL' or 'PYMT' in the last 2 years print 'Flag'
SELECT ACC.Field1
,ACC.Field2
,ACC.Field3
,ACC.Field4
,CASE WHEN
(SELECT Max(DateOfTrans) FROM FinanceTrans FT
WHERE ACC.AccountID = FT.AcctID
AND (TransTypeCode = 'TOLL' AND DateOfTrans >= DATEADD(year, -2, GETDATE()))
AND (TransTypeCode = 'PYMT' AND DateOfTrans >= DATEADD(year, -2, GETDATE()))
GROUP BY AcctID, TransTypeCode) IS NULL
THEN 'Flag'
ELSE ''
AND AS NoNo_Flag
FROM Accounts ACC
WHERE Condition 1, Condition 2...

Answer 1

try this one:
SELECT
acc.*,
CASE WHEN f.acctid IS NULL THEN 'flag' ELSE '' END AS flag_noTollOrPmt
FROM
accounts acc LEFT OUTER JOIN
(SELECT
AcctID,
MAX(DateOfTrans) AS max_dateOfTrans_TollOrPmt
FROM
FinanceTrans
WHERE
DateOfTrans >= DATEADD(YEAR, -2, GETDATE()) AND
TransTypeCode IN( 'TOLL' , 'PYMT')
GROUP BY
AcctID) f ON
acc.acctid = f.acctid

Answer 2

You should be using window functions. The logic is to look at the maximum date for the two transaction types. The flag then depends on the relationship to the current date.
select a.*,
(case when max(case when transtype in ('TOLL', 'PYMT') then DateOfTrans end) over
(partition by acctid) >= dateadd(year, -2, getdate())
then 0 else 1
end) as flag
from accounts;

Answer 3

I could be misunderstanding the question, in which case I can refine my answer. It seems like you just need to check for the existence, or not, of records in the the sub-query. So to that extent do you really need to do an aggregate? And, try using EXISTS:
SELECT ACC.Field1, ACC.Field2, ACC.Field3, ACC.Field4,
CASE WHEN NOT EXISTS
(SELECT DateOfTrans
FROM FinanceTrans FT
WHERE ACC.AccountID = FT.AcctID
AND (TransTypeCode = 'TOLL' AND DateOfTrans >= DATEADD(year, -2, GETDATE()))
AND (TransTypeCode = 'PYMT' AND DateOfTrans >= DATEADD(year, -2, GETDATE())))
THEN 'Flag'
ELSE ''
END AS NoNo_Flag
FROM Accounts ACC
WHERE [*condition*]

Answer 4

So this is how I resolved this issue:
I created a separate column for each, first and then stored those details in a temporary table.
Then I pulled data from the temporary table using conditions to create the flag.
My code is as follows:
SELECT ACC.Field1
,ACC.Field2
,ACC.Field3
,ACC.Field4
,(SELECT Max(DateOfTrans) FROM FinanceTrans FT
WHERE ACC.AccountID = FT.AcctID
AND TransTypeCode = 'TOLL'
GROUP BY AcctID, TransTypeCode) LastTollDate
,(SELECT Max(DateOfTrans) FROM FinanceTrans FT
WHERE ACC.AccountID = FT.AcctID
AND TransTypeCode = 'PYMT'
GROUP BY AcctID, TransTypeCode) LastPymtDate
INTO #Temp_Data
FROM Accounts ACC
WHERE Condition 1, Condition 2...
SELECT ACC.Field1
,ACC.Field2
,ACC.Field3
,ACC.Field4
,CASE WHEN LastTollDate >= DATEADD(year, -2, GETDATE())
AND LastPymtDate >= DATEADD(year, -2, GETDATE())
THEN 'Flag'
ELSE ''
END AS Flag
FROM #Temp_Data