Identifying first occurance of text value in a column

[domdom]

Hi there,

I need a way of identifying the first occurance of a text value in a table.  E.g. in this instance the alphanumeric field "worker id"

 from the following table:

worker id	position id	start date
EP2	6	17/12/2017
EP4	8	04/11/2017
EP4	1	18/10/2017
EP3	7	17/10/2017
EP2	14	29/09/2017
EP1	2	04/08/2017
EP4	13	04/05/2017
EP4	5	26/04/2017
EP1	10	17/04/2017
EP5	4	13/04/2017
EP2	9	11/04/2017
EP1	3	04/04/2017
EP4	11	04/04/2017
EP2	12	30/03/2017

and so the calculated column should show as below:

worker id	position id	start date	First Occurance of Worker id?
EP2	6	17/12/2017	TRUE
EP4	8	04/11/2017	TRUE
EP4	1	18/10/2017	FALSE
EP3	7	17/10/2017	TRUE
EP2	14	29/09/2017	FALSE
EP1	2	04/08/2017	TRUE
EP4	13	04/05/2017	FALSE
EP4	5	26/04/2017	FALSE
EP1	10	17/04/2017	FALSE
EP5	4	13/04/2017	TRUE
EP2	9	11/04/2017	FALSE
EP1	3	04/04/2017	FALSE
EP4	11	04/04/2017	FALSE
EP2	12	30/03/2017	FALSE

Many thanks for any help you can give

Thanks

[Anonymous · Accepted solution]

@domdom,

Based on your sample data, you can create the following columns in your table.

Rank = RANKX(FILTER(Table,Table[worker id]=EARLIER(Table[worker id])),Table[start date],,DESC)

First Occurance of Worker id? = IF(Table[Rank]=1,TRUE(),FALSE())

Regards,
Lydia

[domdom]

you can ignore the position id and the start date