How to use MIN, IFF and Datepart functions together in MS ACCESS? - sql

Question

I have a table like below, I want to group date time entries based on date without time and shifts for example, morning shift starts at 5 AM and ends at 14 PM. Here, MAX function finds the correct date, could you help me to see what's wrong with MIN function?
Indate Incondition
--------- -----------
25.01.2013 05:00:38 KT-RING
25.01.2013 05:21:52 KT-EMPTY
25.01.2013 05:22:00 KT-PROCESS
25.01.2013 06:10:50 KT-RING
25.01.2013 16:10:50 KT-EMPTY
26.01.2013 06:10:50 KT-RING
SELECT Int(Indate) AS DATE,
Min( IIf( ( DatePart('h',[Indate])>=05 AND DatePart('h', [Indate])<13), Indate, 0)) AS FRUHRINGMIN,
Max(IIf((DatePart('h',Indate)>=05 And
DatePart('h',Indate)<13), Indate,0)) AS FRUHRINGMAX
FROM TABLE WHERE Incondition= 'KT-RING'
GROUP BY Int(Indate);
RESULT:
DATE FRUHRINGMIN FRUHRINGMAX
----- ------------- -----------
25.01.2013 00:00:00 25.01.2013 06:10:50
26.01.2013 00:00:00 26.01.2013 06:10:50

Answer 1

I saved your sample data in a table in my Access 2007 database. But when I attempted to run your query, Access threw an error about the alias DATE, which is a reserved word. Bracketing that alias allowed the query to run without error.
SELECT
Int(Indate) AS [DATE],
Min(IIf((DatePart('h',[Indate])>=05 AND DatePart('h', [Indate])<13), Indate, 0)) AS FRUHRINGMIN,
Max(IIf((DatePart('h',Indate)>=05 And DatePart('h',Indate)<13), Indate,0)) AS FRUHRINGMAX
FROM tblJeanneQuadel
WHERE Incondition= 'KT-RING'
GROUP BY Int(Indate);
However the results it gave me did not match what you reported.
DATE FRUHRINGMIN FRUHRINGMAX
41299 1/25/2013 5:00:38 AM 1/25/2013 6:10:50 AM
41300 1/26/2013 6:10:50 AM 1/26/2013 6:10:50 AM
Note my Date/Time values are in US format, but they're actually based on the same values as yours, just displayed differently.
I don't understand why your query result displayed the first column as a date rather than a long integer as mine did and which I would expect as the result from Int(Indate). But that's a minor point; we can convert from one to the other if needed.
More importantly, I'm unsure about what's actually going on. If bracketing [DATE] does not allow your query to run and produce the correct results, try moving the IIf() condition into the WHERE clause. That would greatly simplify your Min() and Max() expressions. But if that still doesn't produce exactly the results you want, show us what it does return and what you want returned instead.