Question

Pig很新，我有一个由奥运会数据组成的数据集 4 - 5年。我想要产生最高和最低的奖牌获胜国家每年分裂。她是一个带标题的样本。

运动员，国家，年份，运动，金牌，银牌，铜牌，

Yang Yilin,China,2008,Gymnastics,1,0,2,3  
Leisel Jones,Australia,2000,Swimming,0,2,0,2  
Go Gi-Hyeon,South Korea,2002,Short-Track Speed Skating,1,1,0,2  
Chen Ruolin,China,2008,Diving,2,0,0,2  
Katie Ledecky,United States,2012,Swimming,1,0,0,1  
Ruta Meilutyte,Lithuania,2012,Swimming,1,0,0,1  
DÃ¡niel Gyurta,Hungary,2004,Swimming,0,1,0,1  
Arianna Fontana,Italy,2006,Short-Track Speed Skating,0,0,1,1  
Olga Glatskikh,Russia,2004,Rhythmic Gymnastics,1,0,0,1  
Kharikleia Pantazi,Greece,2000,Rhythmic Gymnastics,0,0,1,1

我根据自己的知识尝试了我的选择来获得这个，但很少 sucess。这就是我现在拥有的。解决这个问题的任何帮助都将是赞赏！

DEFINE MYOVER org.apache.pig.piggybank.evaluation.Over;    
DEFINE MYSTITCH org.apache.pig.piggybank.evaluation.Stitch; 

A = LOAD 'MortDataSite/MyPigExercise/OlympicMedals.csv' using PigStorage(',') as (ATHLETE:CHARARRAY,COUNTRY:CHARARRAY,YEAR:INT,SPORT:CHARARRAY,GOLD:INT,SILVER:INT,BRONZE:INT,TOTAL:INT);
B = FOREACH A GENERATE YEAR,COUNTRY,TOTAL;  
C = GROUP B BY (YEAR,COUNTRY);  
D = FOREACH C GENERATE FLATTEN(group) as (YEAR,COUNTRY) ,SUM(B.TOTAL);   
E = GROUP D BY (YEAR,COUNTRY);  
F = FOREACH E { 
         E1 = ORDER D BY TOT DESC;
         GENERATE FLATTEN(MYSTITCH(E1, MYOVER(E1,'dense_rank',0,1,1))); 
         }; 

G = FOREACH F GENERATE stitched::YEAR,stitched::COUNTRY ,stitched::TOT,$3;

MyOutput：（考虑到有很多国家拥有相同的TOTAL奖牌，我希望不止一个国家可以分享一个RANK）

(2000,Cuba,65,1)    
(2000,Iran,4,1)    
(2000,Chile,17,1)    
(2000,China,79,1)    
(2000,India,7,1)    
(2000,Italy,65,1)    
(2000,Japan,42,1)    
(2000,Kenya,7,1)   
(2000,Qatar,1,1)   
(2000,Spain,42,1)   
(2000,Brazil,48,1)

预期输出：1

YEAR COUNTRY MAX(TOTAL)       
2001 India  50  
2003 UK     90   
2006 Japan  56

＆安培;

预期输出：2

YEAR COUNTRY MIN(TOTAL)
2001 India  5   
2003 UK     10   
2006 Japan  6

*********更新了查询（按预期运行良好）****

这是更新的查询，它给了我想要的结果。

DEFINE MYOVER org.apache.pig.piggybank.evaluation.Over;    
DEFINE MYSTITCH org.apache.pig.piggybank.evaluation.Stitch; 

A = LOAD 'MortDataSite/MyPigExercise/OlympicMedals.csv' using PigStorage(',') as (ATHLETE:CHARARRAY,COUNTRY:CHARARRAY,YEAR:INT,SPORT:CHARARRAY,GOLD:INT,SILVER:INT,BRONZE:INT,TOTAL:INT);
B = FOREACH A GENERATE YEAR,COUNTRY,TOTAL;  
C = GROUP B BY (YEAR,COUNTRY);  
D = FOREACH C GENERATE FLATTEN(group) as (YEAR,COUNTRY) ,SUM(B.TOTAL);   
E = GROUP D BY (YEAR,COUNTRY); 
F = FOREACH E GENERATE FLATTEN(group) as (YEAR,COUNTRY) ,MAX(D.TOT) as MTOT;
G = GROUP F BY YEAR;
H = FOREACH G {
            G1 = ORDER F BY MTOT DESC;
            GENERATE FLATTEN(MYSTITCH(G1, MYOVER(G1,'dense_rank',0,1,1))); 
              };
     J = FOREACH H GENERATE stitched::YEAR,stitched::COUNTRY ,stitched::MTOT,$3;

**输出：**
    年份最大（总计）。排名
    （2000，美国，242,1）
    （2000年，俄罗斯，187,2）
    （2000年，澳大利亚，182,3）
    （2002年，美国，84,1）
    （2002年，加拿大，74,2）
    （2002年，德国，61,3）
    （2004年，美国，265,1）
    （2004年，俄罗斯，190,2）
    （2004年，澳大利亚，156,3）

Answer 1

如果您希望按国家/地区逐年获得MAX和MIN总奖牌，只需使用MAX和MIN。

B = FOREACH A GENERATE YEAR,COUNTRY,TOTAL;  
C = GROUP B BY (YEAR,COUNTRY);  
D = FOREACH C GENERATE FLATTEN(group) as (YEAR,COUNTRY) ,SUM(B.TOTAL) as TOTAL;   
E = GROUP D BY (YEAR,COUNTRY);    
F = FOREACH E GENERATE group as  (YEAR,COUNTRY),MAX(D.TOTAL);
G = FOREACH E GENERATE group as  (YEAR,COUNTRY),MIN(D.TOTAL);
DUMP F;
DUMP G;

PIG - 获得最高和最高获得最低奖牌的国家，按年度分组

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