Number Repetitions

I have a table with customer invoices,
each row in the table is an invoice.

Some customers have more than one invoice

If the customer has more than one invoice, the name of the customer will be the same on all invoices

How do I get the number of invoices for each customer?

Any idea to help me with this?


Create a relation that links a customer to the customer in the invoice table. Then create a rollup column that does a count from the relation.