how to apply not null in List.contains in power bi

[paw1]

Hi,

I need to create a custom column like below.

Logic: 

if Main Num not repeated in Alternate Num and Alternate Num is not blank then it's parent else child

Please help me to apply  not null of alternate number condition in below logic 

=[A=ah[Main Num],
B=ah[Alterante Num],
to=
if not list.contains(B,[Main Num]) and not null of alternate number then "Parent" else child

[Ahmedx]

perhaps instead of null you will need to write two quotes ""

[Ahmedx]

what type of column b is it text or numbers?
Share some data to work with (in a format the can be pasted in an MS Excel file) and show the expected result.

[paw1]

Hi @Ahmedx 

Thanks for your help. It's the same scenario from this post. https://community.powerbi.com/t5/Desktop/Custom-Column-Creation-help/m-p/3124183#M1057680

I am looking for In first condition how to apply Alternate Num is not blank extra condition?

[Ahmedx · Accepted solution]