大数据第48天—Mysql练习题12道之三-表STG.ORDER-杨大伟

已知一个表STG.ORDER，有如下字段:Date，Order_id，User_id，amount。请给出sql进行统计:数据样例:2017-01-01,10029028,1000003251,33.57。

1）给出 2017年每个月的订单数、用户数、总成交金额。

2）给出2017年11月的新客数(指在11月才有第一笔订单)

drop table if exists test_three_ORDER;


create table test_three_ORDER


(


    `Date` String COMMENT '下单时间',


    `Order_id` String COMMENT '订单ID',


    `User_id` String COMMENT '用户ID',


    `amount` decimal(10,2) COMMENT '金额'


)


row format delimited fields terminated by '	';

--插入数据
insert into table test_three_ORDER values ('2017-10-01','10029011','1000003251',19.50);
insert into table test_three_ORDER values ('2017-10-03','10029012','1000003251',29.50);
insert into table test_three_ORDER values ('2017-10-04','10029013','1000003252',39.50);
insert into table test_three_ORDER values ('2017-10-05','10029014','1000003253',49.50);
insert into table test_three_ORDER values ('2017-11-01','10029021','1000003251',130.50);
insert into table test_three_ORDER values ('2017-11-03','10029022','1000003251',230.50);
insert into table test_three_ORDER values ('2017-11-04','10029023','1000003252',330.50);
insert into table test_three_ORDER values ('2017-11-05','10029024','1000003253',430.50);
insert into table test_three_ORDER values ('2017-11-07','10029025','1000003254',530.50);
insert into table test_three_ORDER values ('2017-11-15','10029026','1000003255',630.50);
insert into table test_three_ORDER values ('2017-12-01','10029027','1000003252',112.50);
insert into table test_three_ORDER values ('2017-12-03','10029028','1000003251',212.50);
insert into table test_three_ORDER values ('2017-12-04','10029029','1000003253',312.50);
insert into table test_three_ORDER values ('2017-12-05','10029030','1000003252',412.50);
insert into table test_three_ORDER values ('2017-12-07','10029031','1000003258',512.50);
insert into table test_three_ORDER values ('2017-12-15','10029032','1000003255',612.50);

-- 1）给出 2017年每个月的订单数、用户数、总成交金额。

select
    date_format(`date`,'yyyy-MM') `date`,
    count(*) `订单数`,
    count(distinct(user_id)) `用户数`,
    sum(amount) `总成交金额`
from test_three_ORDER
group by date_format(`date`,'yyyy-MM');

-- 2）给出2017年11月的新客数(指在11月才有第一笔订单)
select
    t1.user_id
from
(
    select
        user_id
    from test_three_ORDER
    where date_format(`date`,'yyyy-MM') = '2017-11'
    group by user_id
) t1
left join
(
select
    user_id
from test_three_ORDER
where date_format(`date`,'yyyy-MM') < '2017-11'
group by user_id
) t2
on t1.user_id = t2.user_id
where t2.user_id is null;
-- 第二种写法
select
    count(User_id) `11月新客数`
from
(
    SELECT
        User_id,
        Order_id,
        `Date`,
        LAG (`DATE`,1,0) over(partition by User_id order by `Date`) preOrder
    FROM
        test_three_ORDER
) t1
where date_format(`date`,'yyyy-MM')='2017-11' and preOrder=0;