May 15 2022 05:54 PM
May 15 2022 05:54 PM
I have been doing some research online but cant seem to get this right.
If my dates are D1,D2,D3,D4 from MyTable.
How can I show the MIN of those dates?
I need to group by [ID]
I also need to account for Nulls.
I dont know if a function is best or an IIF statement.
let me know if need more info. I tried to keep it simple.
May 16 2022 08:56 PM
1. create a simple query for MyTable
2. View the query in 'design view'
3. Set the column holding your 'date' field to "Descending" (This establishes the priority for the most recent dates) and set the criteria for that column as "Is Not Null" (this will eliminate null values from the query).
4. While still in design view for the query, look for and select the 'Query Design' tab at the top.
5. In the 'Query setup' area, look for the 'Return: All' selection box, and change the 'All' to '5'.
6. This will return the top 5 most recent dates.
* You can manually type in the number '1' in the 'Return:' selection box, This will return only the top 1 entry.
May 17 2022 07:27 AM
The main problem is an inappropriate table design for a relational database application.
Multiple fields of the same thing, named sequentially. XXX1, XXX2, XXX3, etc. always signal this problem.
This is, by the way, what has to be done in Excel because it lacks the ability to manage data relationally. We're not hampered the same way in Access and shouldn't incorporate inappropriate table designs from Excel.
The way to correct the problem is to properly normalize the tables involved. Here is an excellent series of three or four related blog articles describing the problem in more d...
May 17 2022 11:04 AM
Hi, thanks for the response.
I have followed as above but I dont completely understand why I would lmite the results to 5. I would remove records that I need. Maybe I am not understanding or maybe I need to explain a bit further.
I have attached the output based on the query paramters above ( but I am showing ALL).
How would I bel able to return the MIN of the date for each ID?
I assume another query will need to be made. What is tricky is that I need to remove any dates in the past though so if it is a MIN in the record and if <Today then do not consider it.
May 17 2022 02:39 PM
May 17 2022 03:54 PM
May 17 2022 04:38 PM
You should have a table with one record for each type of date and a foreign key to the parent LCID.
The table, therefore, has four fields, including its own Primary Key.
LCID (Foreign key to the parent table)
DateType or DateSequence (NoticeDate, Expirey1Date, Expiry2Date, UltExpireydate)
Now, a query against this table, using Min or Max for SequenceDate, returns the earliest or latest date for each LCID.
SELECT LCID, Min(SequenceDate) as EarliestDate
GROUP BY LCID
SELECT LCID, Max(SequenceDate) as LastestDate
GROUP BY LCID
That would have to be joined back to the parent same table to get the appropriate DateSequence that corresponds to that LCID and date.
SELECT LCID, EarliestDate, DateSequence
FROM tblofExpireyDates INNER JOIN qryofEarliestDates
On tblofExpireyDates.LCID = qryofEarliestDates.LCID and tblofExpireyDates.SequenceDate = qryofEarliestDates.EarliestDate
SELECT LCID, LastestDate, DateSequence
FROM tblofExpireyDates INNER JOIN qryofLatestDates
On tblofExpireyDates.LCID = qryofLatestDates.LCID and tblofExpireyDates.SequenceDate = qryofLatestDates.EarliestDate
May 19 2022 04:15 AM
HI Arnel, you are correct that I am not able to Normalize at this point. It would require a lot of rework. I know of this concept but didnt think to apply it to dates. I know this now so a good lesson brought up by George.
I have looked at the db udf and query. It looks great & performs as intended.
I did leave out a point since I was going to figure out a solution on my own but the function I do not understand how to modify and kindly ask your assistance.
What I need now is to return the MIN but I need to consider the current date.
I will try to summarize in english:
(1) If all dates are >Date() ===>return the MIN (as the UDF does now)
(2) Exclude any dates that are <Date() however if all Dates are <current date then return the MIN of those dates that are <current date.
I hope its not confusing. Grateful for the assistance. thank you in advance. Happy to add more detail if needed.
May 19 2022 04:32 AM - edited May 19 2022 04:57 AMSolution
what do you mean by "current date"? isn't it the same with Date()?
see if the Conditions are met in the new function.
May 19 2022 05:21 AM