SQL Query – second ID of a list ordered by date and ID

I have a SQL database with a list of Customer IDs CustomerID and invoices, the specific product purchased in each invoice ProductID, the Date and the Income of each invoice . I need to write a query that will retrieve for each product, which was the second customer who made a purchase

How do I do that?

EDIT:

I have come up with the following query:

SELECT *,
LEAD(CustomerID) OVER (ORDER BY ProductID, Date) AS 'Second Customer Who Made A Purchase'
FROM a
ORDER BY ProductID, Date ASC

However, this query presents multiple results for products that have more than two purchases. Can you advise?

Answer

I need to write a query that will retrieve for each product, which was the second customer who made a purchase

This sounds like a window function:

select a.*
from (select a.*,
             row_number() over (partition by productid order by date asc) as seqnum
      from a
     ) a
where seqnum = 2;