Solved

How to find the Maximum Date from Columns

Posted on 2015-01-13
13
184 Views
Last Modified: 2015-01-18
I am trying to pick the correct date (Result Date) when comparing two dates in an Access query.  I am able to determine which date to pick first in an IIf statement if one of the date fields is Null by the following function:

=iif(IsNull(Second Date), First Date)

but I haven't been able to figure out how to add the "then" to pick the Maximum of the remaining dates.  So my data currently looks like (see attachment for clearer view of columns):

First Date                    Second Date        Result Date
3/19/2012                      3/19/2012
10/14/2014      10/14/2014      
8/13/2014      11/24/2014      
3/18/2014                      3/18/2014
6/9/2014                6/9/2014
11/4/2013                      11/4/2013
6/20/2014      12/11/2014      
7/14/2014      11/22/2014      
9/10/2013      12/11/2014      
2/6/2014                2/6/2014
7/25/2012                      7/25/2012

I need guidance on how to get the blanks in the Result Date filled in with the max of the two dates.  Hope this makes sense.  Thanks.
C--Users-E221037-Desktop-Capture.PNG
0
Comment
Question by:tomfarrar
  • 6
  • 2
  • 2
  • +2
13 Comments
 
LVL 18

Accepted Solution

by:
Simon earned 250 total points
ID: 40547788
Try
=iif(nz([second date],#1/1/1900#)>nz([first date],#1/1/1900#),nz([second date],null),nz([first date],null))

I haven't got Access in front of me at the moment to test it, but it should give the more recent date of the two, or NULL if both dates are empty.

Or as a column definition in a query...
[Result Date]: IIf(Nz([second date],#01/01/1900#)>Nz([first date],#01/01/1900#),Nz([second date],Null),Nz([first date],Null))
0
 
LVL 7

Author Comment

by:tomfarrar
ID: 40547827
Hi Simon - It is close, but for some reason the second option does not appear to be working.  I am getting the minimum of the Second Date and the First Date.  I need the Max.  Am I looking at this wrong?
0
 
LVL 18

Expert Comment

by:Simon
ID: 40547840
When you say Max, I assume you mean the most recent of the two dates?

Are your fields actually dates or text representations of dates?

I just fired up my laptop to test this and I get the correct results (the later date of the two or the only date if one is blank or empty result column if both dates were blank).

Please let me know the actual dates you are using to test this, and possibly  try some extra test cases
e.g. 1/1/2014 v 12/31/2014
0
Use Case: Protecting a Hybrid Cloud Infrastructure

Microsoft Azure is rapidly becoming the norm in dynamic IT environments. This document describes the challenges that organizations face when protecting data in a hybrid cloud IT environment and presents a use case to demonstrate how Acronis Backup protects all data.

 
LVL 120

Expert Comment

by:Rey Obrero (Capricorn1)
ID: 40547861
try this

ResultDate: IIf([FirstDate]>Nz([SecondDate]),[FirstDate],[SecondDate])
0
 
LVL 7

Expert Comment

by:Robert Sherman
ID: 40547887
Alternatively, especially if you need to do this in more than one query, you can put the below code into a module.

This will give you the max of any number of values, and can be put into your query as
ResultDate: max([FirstDate],[SecondDate])

Function max(ParamArray p()) As Variant

    Dim i As Integer
    
    max = p(0)
    
    For i = 1 To UBound(p)
        If max < Nz(p(i), "") Then
            max = p(i)
        End If
    Next
    
End Function

Open in new window

0
 
LVL 7

Author Comment

by:tomfarrar
ID: 40547894
Hi Simon - They are date-defined in the tables.  Here is the actual function, and the result is shown in the attached.  

LAST_USED_DT: IIf(Nz([Transaction_Dates_JDE]![LST_XFER_DT],#1/1/1900#)>Nz([ConversionDateImport Table]![LST_XFER_DT],#1/1/1900#),Nz([Transaction_Dates_JDE]![LST_USED_DT],Null),Nz([ConversionDateImport Table]![LST_USED_DT],Null))
0
 
LVL 7

Author Comment

by:tomfarrar
ID: 40547897
0
 
LVL 26

Expert Comment

by:Nick67
ID: 40547900
I'd try this

=iif(nz([Second Date],0)>=nz([First Date,0]), [Second Date], First Date)
Nz() is an isnull and iif wrapped together

But what do you want to have happen if both dates are null
0
 
LVL 26

Expert Comment

by:Nick67
ID: 40547907
These make little sense
Nz([Transaction_Dates_JDE]![LST_USED_DT],Null)
Nz([ConversionDateImport Table]![LST_USED_DT],Null)
There's little point in testing for and replacing null just to replace it with null
0
 
LVL 120

Assisted Solution

by:Rey Obrero (Capricorn1)
Rey Obrero (Capricorn1) earned 250 total points
ID: 40547914
@tomfarrar,

you have four date fields, using the date fields listed below
please explain your requirement

[Transaction_Dates_JDE]![LST_XFER_DT]
[Transaction_Dates_JDE]![LST_USED_DT]
[ConversionDateImport Table]![LST_XFER_DT]
[ConversionDateImport Table]![LST_USED_DT]
0
 
LVL 7

Author Comment

by:tomfarrar
ID: 40547924
Thanks, Rey, that is what happens when I get to the end of the day.  My mistake.  Should always be [LST_USED_DT] for both tables.  Now the functions are working.  I am going home, but will be back to confirm in the morning.  Thanks for everyone chipping in.  Sorry for the error.  - Reilly
0
 
LVL 7

Author Comment

by:tomfarrar
ID: 40556501
A lot of good input; thank you.
0
 
LVL 7

Author Closing Comment

by:tomfarrar
ID: 40556507
Thank, Simon, for the immediate answer as it was important.  Thanks, Rey, for the alternative solution, and pointing out my date error.  I am sure the rest of you have provided good detail that I hope to look at closer as time permits.  Thanks again.  - Reilly
0

Featured Post

Ransomware-A Revenue Bonanza for Service Providers

Ransomware – malware that gets on your customers’ computers, encrypts their data, and extorts a hefty ransom for the decryption keys – is a surging new threat.  The purpose of this eBook is to educate the reader about ransomware attacks.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Regardless of which version on MS Access you are using, one of the harder data-entry forms to create is one where most data from previous entries needs to be appended to new records, especially when there are numerous fields and records involved.  W…
QuickBooks® has a great invoice interface that we were happy with for a while but that changed in 2001 through no fault of Intuit®. Our industry's unit names are dictated by RUS: the Rural Utilities Services division of USDA. Contracts contain un…
Learn how to number pages in an Access report over each group. Activate two pass printing by referencing the pages property: Add code to the Page Footers OnFormat event to capture the pages as there occur for each group. Use the pages property to …
In Microsoft Access, learn different ways of passing a string value within a string argument. Also learn what a “Type Mis-match” error is about.

770 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question