I hope someone can help me with my Database Design. I have a table customers where all customers are stored, while they can be of a different type. The type would be "client" or "lead", indicating if it is a actual customer or just a lead.
Now i need a unique CustomerId that is auto-incrementing but only for clients and not for leads. I can't take the id since that value is incrementing for clients and leads.
Did someone solve a similar issue before and give me a approach to getting a incrementing customer-number?