spark统计

http://www.myexception.cn/sql/2004512.html

http://blog.csdn.net/ssw_1990/article/details/52220466

http://www.tuicool.com/articles/uIRZFv

http://mt.sohu.com/20160514/n449468405.shtml

http://blog.csdn.net/asongoficeandfire/article/details/21490101

http://confluence.jetbrains.com/display/IntelliJIDEA/Working+with+Scala+Console

http://my.oschina.net/jamesju/blog/83659

经过资料查询，做几个实验。

基本与sql的实现方式一致，方便理解。

第一步 实现分析 
所有订单中每年最畅销货品： 
1、求出每年每个货品的销售金额

scala>select c.theyear,b.itemid,sum(b.amount) as sumofamount from tbStock a join tbStockDetail b on a.ordernumber=b.ordernumber join tbDate  c on a.dateid=c.dateid group by c.theyear,b.itemid

2、求出每年单品销售的最大金额

scala>select d.theyear,max(d.sumofamount) as maxofamount from (select c.theyear,b.itemid,sum(b.amount) as sumofamount from tbStock a join tbStockDetail b on a.ordernumber=b.ordernumber join tbDate  c on a.dateid=c.dateid group by c.theyear,b.itemid) d group by d.theyear

3、求出每年与销售额最大相符的货品就是最畅销货品

scala>select distinct  e.theyear,e.itemid,f.maxofamount from (select c.theyear,b.itemid,sum(b.amount) as sumofamount from tbStock a join tbStockDetail b on a.ordernumber=b.ordernumber join tbDate  c on a.dateid=c.dateid group by c.theyear,b.itemid) e join (select d.theyear,max(d.sumofamount) as maxofamount from (select c.theyear,b.itemid,sum(b.amount) as sumofamount from tbStock a join tbStockDetail b on a.ordernumber=b.ordernumber join tbDate  c on a.dateid=c.dateid group by c.theyear,b.itemid) d group by d.theyear) f on (e.theyear=f.theyear and e.sumofamount=f.maxofamount) order by e.theyear

第二步 实现SQL语句

scala>hiveContext.sql("select distinct  e.theyear,e.itemid,f.maxofamount from (select c.theyear,b.itemid,sum(b.amount) as sumofamount from tbStock a join tbStockDetail b on a.ordernumber=b.ordernumber join tbDate  c on a.dateid=c.dateid group by c.theyear,b.itemid) e join (select d.theyear,max(d.sumofamount) as maxofamount from (select c.theyear,b.itemid,sum(b.amount) as sumofamount from tbStock a join tbStockDetail b on a.ordernumber=b.ordernumber join tbDate  c on a.dateid=c.dateid group by c.theyear,b.itemid) d group by d.theyear) f on (e.theyear=f.theyear and e.sumofamount=f.maxofamount) order by e.theyear").collect().foreach(println)