topic Re: Set Expression vs If Statement in App Development

Set Expression vs If Statement

H-Zey — Sat, 02 Jul 2022 18:42:52 GMT

I have a Bar chart with an expression that contains a working if Statement:

Count(DISTINCT if( (Field_X = Field_A and Field_Y = Field_B and COUNTRY = 'USA' and TYPE = 'Val'),ID) )

If all the conditions are true I get back a distinct count of IDs.

I have two questions:
(1) Can this be re-written using Set Expression?

I tried re-writing it to the following statement but I'm not getting the correct results. Most likely the use of identifiers and operands are incorrect:

Count(DISTINCT { <Field_X = Field_A>+$1<Field_Y = Field_B>+$2<COUNTRY = {'USA'}>+$3<TYPE = {'Val'}>>} ID)

Any help is greatly appreciated

(2) Is there a difference - performance-wise between the If condition and the set expression or are both the same?

Thanks

Re: Set Expression vs If Statement

sidhiq91 — Sun, 03 Jul 2022 01:48:11 GMT

@H-Zey Yes you can definitely write the above if expression in the form of Set analysis. Please see below.

Count(DISTINCT if( (Field_X = Field_A and Field_Y = Field_B and COUNTRY = 'USA' and TYPE = 'Val'),ID) )

Can be replaced by

Count(distinct {<Field_X={'Field_A'},Field_Y={'Field_B'},COUNTRY={'USA'},TYPE={'VAL'}>}ID)

Secondly Set expression are the preferred choice for writing Complex expression that contains if conditions.

If this answers your question, kindly like and accept it as your solution.

Re: Set Expression vs If Statement

H-Zey — Sun, 03 Jul 2022 16:02:46 GMT

Hi @sidhiq91 ,

Yes! it did work - thank you. I see that you combined all the field all into one set inside the '< > ' tags.

Is that done to treat it as an And?

Will accept it as the solution

Thanks again

Re: Set Expression vs If Statement

sidhiq91 — Sun, 03 Jul 2022 17:16:11 GMT

@H-Zey Yes you are right. Between {} it is treated as AND. I would recommend you to study Set Analysis Topic from our Qlik Community which will help you resolve many issues.

Happy Learning!