A message "No data to display" for a chart. Strange behavior

[sergeyay]

Hello Qliker's,

I try to change a message 'No data to display' for a chart, but it dosn't work properly.

A table looks like this:

Fields Delay_A, Delay_B, Delay_C are integers and have nulls.

Left chart 'Point A' shows # cars where Delay_A is not null (Delay = 0, 1, 5).

When I select 'C' customer, the chart must show nothing ('No data to display' message). I want to change this message to 'No cars at point A'.

So, I did Calculation Condition in chart properties = 'Not IsNull(Delay_A)' and changed Error message for 'Calculation condition unfulfilled', but the chart become empty when Customers unselected!

If I remove calculation condition, I will get the message 'No data to display', but I want 'No cars at point A'  )

What's wrong with it? How does it work? A project in attach.

PS. I think a problem with Nulls.

Count(Delay_A) > 0 works.

Best Regards,

Sergei

[lorenzoconforti · Accepted solution]

=count(if(not IsNull(Delay_A), Car))>0

[sergeyay]

Lorenzo, it works, thank you!

Just now I found this in the article NULL handling in QlikView :

Numerical zero

        If a field has a numerical zero in it – 0 – then this of course represents a numerical nothingness, but it is certainly     not the same as NULL. The field has a value and is hence not NULL. The IsNull() function will return FALSE and the record will be included in the calculation of both Avg() and Count().

I tried this

Count(Delay_A)>0

and it works too!

[lorenzoconforti]

If that's the correct answer, please mark your post as answered