Inter Record Calculations and Sub Queries

[#1]

Hi There,

I have been trying find a Qlikview solution to this.

I have a situaion where I need to check to see if a record exists in the future.  Specifically has a client had a followup appointment within 90 days.  If a client has had an initial appointment, I need to check to see if they have had a follow up within the time frame.  The same client may then come back in a year or so and go through the same process again.

In pure SQL code I would write a sub query to return the values, in this case SQL is not an option, and I am struggling to come up with a solution.

Any help would be appreciated.

Client ID	Appointment Date	Appointment Type	Result (Followup within 90 days)
1	1/1/2010	Initial	Yes
1	2/2/2010	Unrelated	n/a
1	3/2/2010	Followup	n/a
1	4/4/2013	Initial	No
1	5/5/2013	Unrelated	n/a
1	10/10/2013	Followup	n/a

[hic · Accepted solution]

This is a type of problem that you may prefer to solve with SQL than in the QlikView script. Are you sure you cannot use SQL? There are drivers both for text files and for Excel files.

Anyway - if I was to do it in the QlikView script, I would do something along the lines of:

// === All appointments

TempAppointments:

Load *,

          RecNo() as TempAppointmentID

          From Appointments ;

// === Just follow up appointments

Left Join

Load

          ClientID,

          AppointmentDate as FollowUpDate

          resident TempAppointments

          where AppointmentType = 'Followup';

// === All appointments again

Appointments:

Load

          TempAppointmentID as AppointmentID,

          ClientID,

          AppointmentDate,

          FollowUpDate,

          If(FollowUpDate - AppointmentDate > 0 and FollowUpDate - AppointmentDate <= 90, 'Yes', 'No') as HasFollowUp

          resident TempAppointments

          Where ( FollowUpDate - AppointmentDate > 0 or IsNull(FollowUpDate) )

                    and not Exists(AppointmentID,TempAppointmentID) // To get only one record per appointment

          Order By AppointmentDate, FollowUpDate;

Drop Table TempAppointments;

HIC

[#3]

Thank you VERY much Henric, I was having a brain fade and your responce got me back on track.  The use of the exists clause was particularly helpful.

As an aside I could not use SQL as I using an Object Orientated Database and the ODBC connector is very basic, with limited functionality, (pretty much select and group).