Hello, I would like to create a CRM from an existing customer list, with an event management function.

In particular I have: a "customer" table and an "event" table.

Customers must register for the event by submitting a form (which inserts data into the "event" table). When the customer already exists, a tag is created into the "customers" table referring to the event. Or in any case a link between the "customers" table and the "list" table.

Do you have any suggestions? Thank you!