Hi can anybody tell me how to get the latest data logged in database while sending the query. Like i have MS Access database in which i have logged data along with time-stamping, so when i send a query i should get only the latest information stored in it or get the latest data from it based on the last recorded time.
My access database has the following data:
DEVICENAME WINDOW DATE TIME
Device1 WIN1 6/10/2013 11:16 AM
Device1 WIN2 6/10/2013 11:16 AM
Device2 WIN7 6/10/2013 11:16 AM
Device2 WIN7 6/10/2013 11:16 AM
Device1 WIN1 6/10/2013 11:20 AM
Device1 WIN2 6/10/2013 11:20 AM
Device1 WIN3 6/10/2013 11:20 AM
As you can see device1 is logged twice @ different intervals, but from these logged data i need only the latest logged data i.e., device1 logged @ 11:20AM. How do i initiate a query for this case.
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Jagadisha NPosted Jun 10, 2013, 7:50 AM
Thanks for your reply, but i also want to return device name & its latest timestamp data. So with the query you have posted i may retrieve only the latest or max of datetime, for retrieving device name if i include a query like shown below:
"SELECT window, Time from ErrorLog where DEVICENAME='" + btn[add].Text + " and Time = (SELECT MAX(Time)) from ErrorLog"
I get an error like this:
Cannot have Memo, OLE, or Hyperlink Object fields in aggregate argument (time).
How to resolve this?
Thanks in advance,
Jagadisha.N
Vijay YadavPosted Jun 10, 2013, 6:33 AM
Can you please tell us, is it necessary to have to different column for date and time?
if not then it can be resolved easliy by the below query
select * from tablename where datecolumn = (select max(datecolumn) from tablename)
or else you need to have a 2 conditions in where clause one for date and another for time.