topic Using QVD files to build historical data in QlikView

Using QVD files to build historical data

Wed, 03 Jun 2009 18:34:40 GMT

Hi,

I need to store QVDs on a weekly basis of some data read in from an Excel file.
Somehow I also need to stamp each one with a date field, and also incorporate that date in the qvd file name.

Can anyone tell me how I can include it in the filename?
The LOAD statement will obviously contain the date field Now().

also, is there a way of instead of creating a date field in the table, to have a counter? like a filenumber, which increments each time the qvd is stored?

Sorry, a few things in one there..

thanks in advance,

Matt

Using QVD files to build historical data

Wed, 03 Jun 2009 18:56:57 GMT

For storing the QVD Files, use a variable in the following way:

Let V=Date(Today(),'YYYYMMDD');

Store TableX into TableX_$(V).qvd;

You can use the variable to keep the sequence number if you want to use it instead of the dates.

Using QVD files to build historical data

Mon, 08 Jun 2009 15:20:23 GMT

Thanks for the response, I can get that working now.

I would, howver still like to know, if there is a clever solution out there for maybe sequentially numbering each qvd rather than timestamping it.

Can anybody think of any clever ways to do this - I am stumped..

Thanks in advance,

Matt

Using QVD files to build historical data

Mon, 08 Jun 2009 21:10:53 GMT

You could have a variable that is set first time when the application is reloaded and after that increased by 1 every reload. Use that variable at the beggining of the file name.

if isnull(counter) or len(counter)=0 then
set counter = 1;
end if

store tmp into $(counter)_history.qvd;

when loading history data you can that itterate i from 1 to counter and load like this:

concatenate(history)
load *, '$(i)' as historyID

from [$(counter)_history.qvd] (qvd);

Using QVD files to build historical data

Mon, 08 Jun 2009 21:12:10 GMT

Hi Matt,

What i have shown is the way to control the name of QVD Files using variables. Instead of storing TimeStamp, you could assign a number to the variable, and that should be sufficient for sequentially numbering your files.