topic Re: qvd files in same directory with different fields in QlikView

qvd files in same directory with different fields

Thu, 09 Mar 2017 14:17:52 GMT

I have an extract that stores a new qvd file in the same directory everyday. The files are called accounts_$(v_todays_date).qvd

Then when I pull the files in the data model my FROM statement is just:

FROM (qvd)

So it pulls in every file in the directory.

This has worked fine so far since I have not needed to add any fields. However, I am in a situation that I do need to add a field to the files going forward. I am wondering if there is a way to keep my current structure and somehow ignore the fact that there is a new field in some of the qvd files. Like something that I can put in the LOAD that says if the field doesn't exist in one of the qvd files just make it null. Is this possible?

Re: qvd files in same directory with different fields

adamdavi3s — Thu, 09 Mar 2017 14:46:11 GMT

I hate to say it but does just using this work:

Load *

FROM (qvd)

It depends what you then do with those fields I guess, but you can't be doing much if you're aiming for optimised qvd loads anyway.

Re: qvd files in same directory with different fields

Aurelien_Martinez — Thu, 09 Mar 2017 14:49:38 GMT

Hi,

You can try a loop in your directory like:

MyTable:

Load

Inline [

];

for each vfile in filelist("directoryName")

concatenate(MyTable)

Load

From $(vfile)(qvd)

;

next vfile

Re: qvd files in same directory with different fields

adamdavi3s — Thu, 09 Mar 2017 14:50:46 GMT

Hmm no that creates a synthetic key... bear with me

Re: qvd files in same directory with different fields

adamdavi3s — Thu, 09 Mar 2017 14:54:01 GMT

Yep this resolves the issue I was having with the synthetic key, and actually you don't even need the loop

transactions:

load * INLINE [

TransCounter

];

concatenate(transactions)

load *

from accounts_*.qvd(qvd);

Re: qvd files in same directory with different fields

Aurelien_Martinez — Thu, 09 Mar 2017 14:57:33 GMT

ah, ok great

Re: qvd files in same directory with different fields

Thu, 09 Mar 2017 18:12:41 GMT

What is the purpose of 'TransCounter' in this example? I don't currently have a field like that in my existing qvd files and I am unable to recreate them.

Re: qvd files in same directory with different fields

adamdavi3s — Thu, 09 Mar 2017 18:40:24 GMT

hi Matt,

it can be any field from your QVD at all, just replace it with any one. The load inline is just required to create the table so you can then concatenate it