题解 | #店铺订单分析#

与上一题差不多，就是需求有些绕，其实求发一样，单量都给了，进行判断在分组求
方法一:if方法
select 
t.订单数区间,
count(客户编码) as "人数"
from(
select 
客户编码,
if(订单数 between 0 and 2,"0-2",if(订单数 between 3 and 5 ,"3-5","5单以上")) as "订单数区间"
from 订单表
) as t 
group by t.订单数区间
order by t.订单数区间

方法二:case when then end
select 
t.订单数区间,
count(客户编码) as "人数"
from(
select 
客户编码,
case when 订单数 between 0 and 2 then "0-2"
     when 订单数 between 3 and 5 then "3-5"
     when 订单数>5 then "5单以上" end  as "订单数区间"
from 订单表
) as t 
group by t.订单数区间
order by 订单数区间