Get Sales for the date campaign Launched

[ibradly]

I am trying to output the sales for the date that the campaign launched. I don't want sales for any other day.

Date:              Campaign:         Sales:

01/01/18        Campaign 1      $18,000

01/01/19        Campaign 1      $17,500

01/01/20        Campaign 2      $16,000

01/01/21        Campaign 2     $19,000

The date launched for Campaign 2 was launched on the 20th therefore the output should be $16,000

I tried using the min() and max(function) but that only works if its at the beginning of the week or at the end of the week it doesnt solve if the campaign launched in the middle of the week. 

Thats why i want to pull only the date the campaign launched on.

Not sure what other functions are out there that I can use to solve his problem. I am using set analysis.

Can someone please help me? I am new to qlik.

[Vegar · Accepted solution]

=sum(Sales) * (Date=Min(total <Campaign> Date))*-1

[ibradly]

It worked!! Thank you!

[ibradly]

Can you please explain the logic behind this expression? I don't quite understand how it works. 

Thanks.

[Vegar]

=sum(Sales)  //tour calculation

*

(Date=Min(total <Campaign> Date)) // return -1 if true 0 if false

*-1 // multiply with -1 to reverse the impact of true above. -1 x -1= 1