topic Re: Null values becoming "-" when using window function in App Development

Null values becoming "-" when using window function

PaulinePlassart — Fri, 16 Aug 2024 11:31:00 GMT

Dear community !

I'm using Qlik Sense on windows May 2024, I try to use window function in script.

But I noticed that when adding a window function in my table all null values of the table are transformed as "-".

You'll found attached a small exemple.

Is that normal or already reported as bug ?

Is there a workaround in order to keep null values as null ?

Regards,

Pauline

Re: Null values becoming "-" when using window function

pchatziag — Sat, 17 Aug 2024 22:17:43 GMT

Hi Pauline,

I had exactly the same problem this week in my project and created a support case. It seems like a bug to me and should be fixed. I provided a similar app showcasing the error and wait for further details.

I can think of a lot of workarounds to this. The most obvious solution is to avoid (for the time being) using the window function and use a resident load with a group by statement instead, which will be joined to the initial table.

Solution 1:

Result 1:

Now if you insist on using the Window function, then you should try to convert the created '-' to a NULL. Unfortunately, you cannot do it in the same Load statement, in which the Window function is applied (this seems like another problem of this otherwise useful function). You can use instead a preceding load (link).

Solution 2:

Result 2:

I hope this was helpful.

Best regards,

Prodromos

Re: Null values becoming "-" when using window function

PaulinePlassart — Mon, 19 Aug 2024 16:11:33 GMT

Thank you for your answer !

I will follow release notes on coming patches and wait to try this new feature !

Finally I used the window function of SQL Server in order to avoid a join or second load...

Regards,

Pauline

Re: Null values becoming "-" when using window function

pchatziag — Tue, 01 Oct 2024 21:03:46 GMT

Hi Pauline,

the issue has been fixed on Qlik Cloud. I tested and could not replicate the error.

Best Regards,

Prodromos