topic Re: Auto Concatenation not working ? in QlikView

Auto Concatenation not working ?

richard_chilvers — Wed, 21 Dec 2016 13:45:47 GMT

Is there a situation when 2 identical tables don't concatenate?

I am building a table from external sources which allow only 100 records to be extracted at a time. So I am using a loop to extract batches of 100 at a time into a RESULTS table.

Of course each batch has identical fields, but I'm getting many tables called RESULTS-n, joined by a synthetic table.

Advice please on what is stopping me getting a single table?

Re: Auto Concatenation not working ?

giakoum — Wed, 21 Dec 2016 13:50:53 GMT

Can you please share the code?

Autoconcatenate works

Re: Auto Concatenation not working ?

sunny_talwar — Wed, 21 Dec 2016 13:54:00 GMT

Are you absolutely certain that the all of them have the same columns? May be an extra column get picked if you use LOAD *?

Re: Auto Concatenation not working ?

richard_chilvers — Wed, 21 Dec 2016 14:04:53 GMT

Hi Sunny

Since its just a loop in the script, I think the fields must be identical. This is what I get when I run the loop just one time:

Re: Auto Concatenation not working ?

sunny_talwar — Wed, 21 Dec 2016 14:06:49 GMT

Would you be able to share the loop part of the script?

Re: Auto Concatenation not working ?

giakoum — Wed, 21 Dec 2016 14:09:42 GMT

Most likely you are not specifying the table name so Qv assigns its own naming

Re: Auto Concatenation not working ?

richard_chilvers — Wed, 21 Dec 2016 14:18:36 GMT

As you see above, I am naming the table 'Responses'.

Re: Auto Concatenation not working ?

richard_chilvers — Wed, 21 Dec 2016 14:19:54 GMT

Hi Sunny

What are you thinking might be the issue? As you see passes 1 & 2 of the loop generate identical columns.

Re: Auto Concatenation not working ?

giakoum — Wed, 21 Dec 2016 14:30:25 GMT

Then it is either something in your code or QV version. What version are you using?

Re: Auto Concatenation not working ?

swuehl — Wed, 21 Dec 2016 14:35:21 GMT

You are not coping with multiple tables (like joining two tables) in a single loop run, are you?

Re: Auto Concatenation not working ?

sunny_talwar — Wed, 21 Dec 2016 14:36:05 GMT

I am having a feeling that somehow there is either a noconcatenate in the script or you have additional fieldnames which gets dropped at a later point... might be easier to point out by looking at the script

Re: Auto Concatenation not working ?

richard_chilvers — Wed, 21 Dec 2016 14:50:54 GMT

Hi Stefan

Yes I am. Might this cause an issue ?

Re: Auto Concatenation not working ?

swuehl — Wed, 21 Dec 2016 14:59:45 GMT

Yes, could break the expected auto-concatenation.

As already suggested, could you please post your relevant script part?

Re: Auto Concatenation not working ?

richard_chilvers — Wed, 21 Dec 2016 15:15:48 GMT

It will be quite a bit of work for me to share the code.

So I will use your hint to try to re-organise how I load the data and see if I can avoid the issue first.

Thanks

Re: Auto Concatenation not working ?

rwunderlich — Wed, 21 Dec 2016 16:37:36 GMT

Certain script structures such as preceeding load or joins will "break" auto concatenation. You can usually fix this by using the Concatenate keyword to force concatenation.

-Rob

http://masterssummit.com

http://qlikviewcookbook.com

Re: Auto Concatenation not working ?

richard_chilvers — Wed, 21 Dec 2016 16:53:47 GMT

Thanks Stefan (and Sunny)

Based on your hints on where to look, I think I have found the issue: I was dropping fields within the loop, which I guess would confuse the AUTOconcatenate.

Re: Auto Concatenation not working ?

piotr-bratek — Fri, 15 Oct 2021 15:22:54 GMT

Hi Rob,
do you know if there is any official material when you can find more details regarding how auto concatenation may be affected by preceding loads, joins, etc. ?

Cheers
Piotr

Re: Auto Concatenation not working ?

johnca — Mon, 18 Oct 2021 21:31:48 GMT

I get that when I use a path and loop, if I also add NoConcatenate...

vPath = '\\qv_user_files\'

For each File in FileList('$(vPath)*_My_Data_Files.csv')

First 100
data:
NoConcatenate
LOAD

Field1,

Field2,

Field3

From $(File);

It works perfectly if I do not.