Check for earliest date in table for comparison using M results in cyclic error

[Anonymous]

In Power Query, I have a table which has a date column. I want to write a custom column that checks if the date is the minimum date for that field, then return true, else false.

if List.Contains({List.Min(#"Table"[Date])},[Date]) then true else false

Do I need to have a separate object for comparison? I would never use this minimum date in another location, and if possible would like to avoid creating a referenced table or something similar.

[v-yulgu-msft · Accepted solution]

Hi @Anonymous,

To get the minimum date in a column, please refer to this syntax:

AddCustom = Table.AddColumn(PreviousStep, "Custom", each List.Max(PreviousStep[a]))

Then, wrap above step inside an if condition.

= Table.AddColumn(#"Changed Type", "Custom.1", each if [Date]=List.Min(#"Changed Type"[Date]) then "true" else "false")

Best regards,

Yuliana Gu

[ratercero]

Hello @v-yulgu-msft,

what condition would I need to add in order to get the minimun date for each site?

Best Regards

[Anonymous]

@ratercero I ended up just bringing in a second reference to the table for another situation, grouping on the ID and value, then merging it in to make it work. I found that even if I could make more of it work in a single step that it ended up hurting readability for anyone else coming in after me.