MYSQL系列（5） 电商常用指标查询

表:order ,字段：orderid, userid, isPaid, price, paidTime

表:user,字段: userid, sex, birth

1.统计不同月份下单人数

select month(date_format(paidtime, '%Y-%m-%d')), count(distinct userid)
from order
where isPaid = '已支付'
group by month(date_format(paidtime, '%Y-%m-%d'));

2.统计3月份回购率和复购率

2.1 3月份复购率

复购率：3月份中购买两次以上的人数占3月份总购买人数的比例

​ 3月份购买人数

select userid, count(userid) as count_userid
from order
where ispaid = '已支付'
and month(date_format(paidtime, '%Y-%m-%d')) = 3
group by userid;

​ 复购率 =3月份购买两次以上的人数/ 对3月份复购人数统计去重

select count(t.userid) as 购买人数, count(if(t.count_userid>1, 1, null)) as '复购人数',
	   count(if(t.count_userid>1, 1, null)) / count(t.userid) as '复购率'
from (select userid, count(userid) as count_userid
     from order
     where ispaid = '已支付'
     and month(date_format(paidtime, '%Y-%m-%d')) = 3
     group by userid
      ) t

2.2 用户回购率

​ 运用子查询，筛选出第二个月有购买记录的情况，然后进行count

select t1.m, count(t1.userid), count(t2.userid)
from	(select userid), date_format(paidtime, '%Y-%m-01') as m
		from order 
		where ispaid = '已支付'
		group by userid, date_format(paidtime, '%Y-%m-01')
		) as t1
left join
		(select userid, date_format(paidtime, '%Y-%m-01') as m
        from order
        where ispaid = '已支付'
        group by userid,  date_format(paidtime, '%Y-%m-01')
        ) as t2
on 		t1.userid = t2.userid and t1.m = date_sub(t2.m, INTERVAL 1 month)
group by t1.m

3. 统计第一次和最后一次消费间隔多久

   select userid, datediff(max(paidtime), min(paidtime))
   from order
   where ispaid = '已支付'
   group by userid
   having count(1) > 1