I am trying to count customer and non-customer in my master-DE. Having a customerID means he is an customer.
SELECT SUM(CASE WHEN a.customerID is not null THEN 1 ELSE 0 END) AS 'Customer', SUM(CASE WHEN a.customerID is empty THEN 1 ELSE 0 END) AS 'Lead', FROM MasterNewsletter
But I am getting that error message "Automation failed due to system error." When I am adding another field I can see that I don´t get results in both columns. Field "customerID" is numeric.