How many customers are there
select count ( * ) from customers
How many of them have a coupon amount of 500
select count ( * ) from customers as t1 join discount_coupons as t2 on t1.coupon_id = t2.coupon_id where t2.coupon_amount = 500
What is their customer id
select t1.customer_id from customers as t1 join discount_coupons as t2 on t1.coupon_id = t2.coupon_id where t2.coupon_amount = 500
Are they a good or bad customer
select t1.good_or_bad_customer from customers as t1 join discount_coupons as t2 on t1.coupon_id = t2.coupon_id where t2.coupon_amount = 500