Check if we have a new record next day

Question

I have this tale:

ProductName	Date
A	01.02.2020
B	01.02.2020
A	02.02.2020
B	02.02.2020
C	02.02.2020

I want to add a new column that is a binary column, showing 1 for a record that did not exist on a previous day.

For product C I should get 1 and for A and B - 0:

ProductName	Date	Flag
A	01.02.2020	0
B	01.02.2020	0
A	02.02.2020	0
B	02.02.2020	0
C	02.02.2020	1

Answer 1

I see that for the absolute minimum date you do not want to return 1. In this case you could use this calculated column formula:

Flag = 
VAR _prod = [ProductName]
VAR _date = [Date]
VAR _prod_exists_day_ago = NOT(COUNTROWS(FILTER('TableName', [ProductName] = _prod && [Date] = _date-1)))
RETURN INT(IF([Date] <> MIN([Date]), _prod_exists_day_ago))