第十课 分组数据创建分组过滤分组分组和排序

select vend_id, count(*) as num_prods
from products
group by vend_id;

select cust_id, count(*) as orders
from orders
group by cust_id
having count(*) >= 2;

select vend_id, count(*) as num_prods
from products
where prod_price >= 4
group by vend_id
having count(*) >= 2;

select order_num,count(*) as items
from orderItems
group by order_num
having count(*) >= 3
order by items, order_num;