topic Re: Do While ...Loop continued working after the condition became invalid in QlikView

Do While ...Loop continued working after the condition became invalid

Anonymous — Mon, 12 Mar 2018 13:32:08 GMT

Hello!

I write some code as

set FirstYear=2016;

Let CurrentYear = Year(Today()); //2018

......

DO while $(FirstYear) <= $(CurrentYear)

$(vTable)__c_Final:

SQL SELECT *

FROM

$(vTable) Where CreatedDate>= $(FirstYear)-01-01T00:00:00.000+0000 and CreatedDate<= $(FirstYear)-12-31T00:00:00.000+0000;

Let FirstYear = $(FirstYear)+1;

DROP $(vTable)_Final

SLEEP 1000;

LOOP

....

This code started working and continued working after the condition became invalid! It works with FirstYear = 2016 (true), 2017 (true), 2018(true), 2019 ( false!!) and so on. And when I debug it I don't see "Do.." string in debug cycle. When I write condition in 'LOOP' string, cycle works true:

DO...

LOOP while $(FirstYear) <= $(CurrentYear)

works true.

Could you please tell me why cycle does not work in first case?

Re: Do While ...Loop continued working after the condition became invalid

Digvijay_Singh — Mon, 12 Mar 2018 18:47:28 GMT

not sure but I think you don't need to use 'Let' in below statement as the variable is already defined at the top, looks like its kind of creating FirstYear newly inside the loop -

Let FirstYear = $(FirstYear)+1; change this to

FirstYear = $(FirstYear)+1;

Re: Do While ...Loop continued working after the condition became invalid

rwunderlich — Mon, 12 Mar 2018 20:06:42 GMT

You should not use $() around FirstYear in the Do condition:

DO while FirstYear <= $(CurrentYear)

-Rob

http://masterssummit.com

http://qlikviewcookbook.com

Re: Do While ...Loop continued working after the condition became invalid

Anonymous — Tue, 13 Mar 2018 06:44:50 GMT

No, I used this code

FirstYear = $(FirstYear)+1;

and had same result.

Re: Do While ...Loop continued working after the condition became invalid

Anonymous — Tue, 13 Mar 2018 07:06:06 GMT

No, you code don't work too

Re: Do While ...Loop continued working after the condition became invalid

Anonymous — Tue, 13 Mar 2018 07:09:17 GMT

Sorry!!!!! I hurried.

You where right!

Re: Do While ...Loop continued working after the condition became invalid

onmysi49 — Thu, 05 Nov 2020 10:49:48 GMT

Hello Rob,

I have a question regarding this very old post.

Today I also found out that using dollar sign expansion does not work in certain cases. See my case below:

Do while ($(#vRefDate) <= $(#vEndDate)) . . . Let vRefDate = AddMonths($(#vRefDate),+1); Loop

This does not work. I have to either move the condition to the end of the loop like this:

Do . . . Let vRefDate = AddMonths($(#vRefDate),+1); Loop while ($(#vRefDate) <= $(#vEndDate))

Or I have to remove the dollar sign expansion from vRefDate variable in the condition like this:

Do while ((vRefDate) <= $(#vEndDate)) . . . Let vRefDate = AddMonths($(#vRefDate),+1); Loop

But my question is why? What is the cause that the Loop while works with dollar sign exp. and Do while does not? From time to time I am confused by behaviour of dollar sign expansion, which is quite tricky to understand in different use cases.

I only found this https://support.qlik.com/articles/000073866 article but that does not give me the explanation.

Thanks a lot. Have a great day.

Re: Do While ...Loop continued working after the condition became invalid

Marius_ — Wed, 12 Jul 2023 10:32:33 GMT

I had the same problem and removed the $() from the second condition as well, like:

do while $(vInRes) < $(vUitRes)

-> do while vInRes < vUitRes

and it worked