电商交易项目案例
--字段含义--
Sdate定义了日期的分类，将每天分别赋予所属的月份、星期、季度等属性，
字段分别为日期、年月、年、月、日、周几、第几周、季度、旬、半月；
Stock定义了订单表头，字段分别为订单号、交易位置、交易日期；
StockDetail文件定义了订单明细，该表和Stock以交易号进行关联，
字段分别为订单号、行号、货品、数量、价格、金额；
--创建sdate表--
CREATE TABLE sdate(
dateID string, --日期
theyearmonth string,--年月
theyear string,--年
themonth string,--月
thedate string,--日
theweek string,--周几
theweeks string,--第几周
thequot string,--季度
thetenday string,--旬
thehalfmonth string --半月
)
ROW FORMAT DELIMITED FIELDS TERMINATED BY ','
LINES TERMINATED BY '
' ;
--创建stock表--
CREATE TABLE stock(
ordernumber string,--订单号
locationid string,--交易位置
dateID string --日期
)
ROW FORMAT DELIMITED FIELDS TERMINATED BY ','
LINES TERMINATED BY '
' ;
--创建stockdetail表--
CREATE TABLE stockdetail(
ordernumber string,--订单号
rownum int,--行号
itemid string, --货品
qty int, --数量
price int, --价格
amount int --总金额
) ROW FORMAT DELIMITED FIELDS TERMINATED BY ','
LINES TERMINATED BY '
' ;
创建表，导入数据
load data local inpath '/home/lan/sdate.txt'
overwrite into table sdate;
load data local inpath '/home/lan/stock.txt'
overwrite into table stock;
load data local inpath '/home/lan/stockdetail.txt'
overwrite into table stockdetail;
1、计算所有订单每年的总金额
算法分析：
要计算所有订单每年的总金额，首先需要获取所有订单的订单号、订单日期和订单金信息，
然后把这些信息和日期表进行关联，
获取年份信息，最后根据这四个列按年份归组统计获取所有订单每年的总金额。
select a.theyear,sum(c.amount) from sdate a,stock b,stockdetail c where a.dateID=b.dateID and b.ordernumber=c.ordernumber group by a.theyear;
2、计算所有订单每年最大金额订单的销售额
算法分析：
该算法分为两步：
1）按照日期和订单号进行分组计算，
获取所有订单每天的销售数据；
select a.dateid, a.ordernumber,sum(b.amount) as sumofamount
from stock a,stockdetail b
where a.ordernumber=b.ordernumber
group by a.dateid,a.ordernumber;
2）把第一步获取的数据和日期表进行关联获取的年份信息，
然后按照年份进行分组，使用Max函数，获取所有订单每年最大金额订单的销售额。
select c.theyear,max(d.sumofamount) from sdate c,
(select a.dateid, a.ordernumber,sum(b.amount) as sumofamount
from stock a,stockdetail b
where a.ordernumber=b.ordernumber
group by a.dateid,a.ordernumber)d
where c.dateid=d.dateid
group by c.theyear order by c.theyear;
3、统计所有订单中季度销售额前10位
select c.theyear,c.thequot,sum(b.amount) as sumofamount
from stock a,stockdetail b,sdate c
where a.ordernumber=b.ordernumber and a.dateid=c.dateid
group by c.theyear,c.thequot
order by sumofamount desc limit 10;
4、列出销售金额在100000以上的单据(订单号)
select a.ordernumber,sum(b.amount) as sumofamount
from stock a,stockdetail b
where a.ordernumber=b.ordernumber
group by a.ordernumber
having sumofamount>100000;
5、所有订单中每年最畅销货品
第一步：
统计出每年每种货品的销售总金额
stock a,stockdetail b,sdate c
===================================
select c.theyear,b.itemid,sum(b.amount) as sumofamount
from stock a,stockdetail b,sdate c
where a.ordernumber=b.ordernumber and a.dateid=c.dateid
group by c.theyear,b.itemid;
第二步:
在第一步的数据上，统计出每年最大的销售总金额
将第一步的数据集起别名为d;
select d.theyear,max(sumofamount) as maxofamount from
(select c.theyear,b.itemid,sum(b.amount) as sumofamount
from stock a,stockdetail b,sdate c
where a.ordernumber=b.ordernumber and a.dateid=c.dateid
group by c.theyear,b.itemid) d
group by d.theyear;
第三步：所有订单中每年最畅销货品
e:每年每种货品的销售总金额
f:每年最大的销售总金额
select distinct e.theyear,e.itemid,f.maxofamount from
(select c.theyear,b.itemid,
sum(b.amount) as sumofamount from stock a,stockdetail b,sdate c
where a.ordernumber=b.ordernumber and a.dateid=c.dateid
group by c.theyear,b.itemid) e,
(select d.theyear,max(d.sumofamount) as maxofamount from
(select c.theyear,b.itemid,sum(b.amount) as sumofamount
from stock a,stockdetail b,sdate c
where a.ordernumber=b.ordernumber and a.dateid=c.dateid
group by c.theyear,b.itemid) d
group by d.theyear) f
where e.theyear=f.theyear and e.sumofamount=f.maxofamount
order by e.theyear;