[AccessD] group min - max

Dear Stuart and Jack,

thanks for the help.

Best Wishes

Pedro


At 21:30 6-12-2010, you wrote:
>How do you decide which record to use here:
> > 002    3-2-10    8
> > 002    3-2-10    6
>
>If there only one entry per day per patient, you can use Order By 
>and First/Last.
>
>Select pID, First(pDate),First(POtherValue)
>from tblPatientData
>Group By pID
>Order by pID,pDate.
>
>It would be a good idea to index the table on pID,pDate :-)
>
>If there are multiple entries per day, you need a way to identify 
>which  record you want.  For
>the data and results given, this would work
>
>...
>Order by pID,pDate,pOtherValue
>
>If you want the maximum value on the first date, use
>
>...
>Order by pID,pDate,pOtherValue DESC
>
>
>--
>Stuart
>
>On 6 Dec 2010 at 13:36, pedro at plex.nl wrote:
>
> > Dear list,
> >
> > normally i use Group by and min max, to create a list of min or max
> > (or first-last) dates per Patient.
> >
> > But when there is a third column which has different values, I'll make
> > a key from date and patient-number and then ad the extra value. How
> > can i do this in one simple query?
> >
> > I have
> >
> > 001    1-1-10    5
> > 001    2-2-10    7
> > 002    3-2-10    8
> > 002    3-2-10    6
> >
> > i need
> >
> > 001    1-1-10    5
> > 002    3-2-10    6
> >
> > Thanks
> >
> > Pedro
> > --
> > AccessD mailing list
> > AccessD at databaseadvisors.com
> > http://databaseadvisors.com/mailman/listinfo/accessd
> > Website: http://www.databaseadvisors.com
> >
>
>
>--
>AccessD mailing list
>AccessD at databaseadvisors.com
>http://databaseadvisors.com/mailman/listinfo/accessd
>Website: http://www.databaseadvisors.com