Finding max of multiple rows for every customer

[Joernolav]

Hi.

I have two tables. One named External_Contact which contains customers and one table named G_MainL which contains invoices  and a column named paydate.

They are connectd with columns Kundenr and Contid one-to-many.

I need a column in External_Contact that show the last payment date for each customer.

I have tried the following for a new column but get an error.

last_payment = LOOKUPVALUE(Max(G_MAINL[Paydate]); External_Contact[Kundenr]; G_MainL[Contid])

I get the error: " Lookupvalue expects a column reference as argument number 1."

what am I doing wrong?

Thank you for your help.

[OwenAuger · Accepted solution]

Hi @Joernolav

Since you have a relationship between the two tables, you can use this formula as a calculated column in External_Contact:

last_payment =
CALCULATE ( MAX ( G_MainL[Paydate] ) )

Since this is calculated within the row context of External_Contact, the CALCULATE results in context transition, effectively adding the current row's customer to the filter context, which in turn filters G_MainL.

MAX ( G_MainL[Paydate] ) is then evaluated over the rows of G_MainL corresponding to that customer.

Cheers,

Owen

[Joernolav]

Thank you. That solved the problem.