I am trying to write a SQL query that returns the number of products that each customer has and lists the products on one line.

For example I have a database that contains CustomerID and Product and obviously if the Customer has multiple products there are multiple rows in the database. So if CustomerID '123' has Products 'X', 'Y' and 'Z' I want a query that lists the following

CustomerID #_of_Products Products
123 3 X, Y, Z

How would I go about doing this? Thanks