Determining if a Parent has at least one child.

[Jeff2Jets]

I have two tables, as seen below:

The Customer (Parent) table contains:

• Customer ID
• Customer Name

The Purchase (Children) table contains:

• Customer ID
• Product ID
• Product Name

This is a one-to-many relationship. The two tables are related by the Customer ID. I want to create a new column in the Customer table that contains a Boolean value reflecting if the Customer has any Purchase records. I tried LookupValue, but then receive an error when there are more than one Purchase record.

[vojtechsima · Accepted solution]

Hi, @Jeff2Jets 
check this:

DidPurchase? = 

var currentcustomer = Customer[customerID]
var checkPurchase = COUNTROWS(FILTER(Purchase, Purchase[customerID] = currentcustomer))

return if ( checkPurchase >= 1, TRUE(), FALSE())

[Jeff2Jets]

That was perfect, thanks!