How many customers are there?
select count ( customer_id ) from customers
When did the last customer come?
select date_became_customer from customers order by date_became_customer desc limit 1
How about the first?
select date_became_customer from customers order by date_became_customer limit 1
Can you show me the names of the first five customers?
select customer_name from customers order by date_became_customer limit 5