Apache Pig 中的计数/求和

Question

我是 Apache Pig 的初学者。有一个包含以下字段的表：

table - amount:long date:string country:string

最初，我的目标是按月计算每个国家/地区的字段数量。例如，这将是我需要的最终结果：

(Exhibit A)
201201 USA 100
201201 UK 150
201305 ITALY 200
201305 USA 120
201305 UK 20
201403 ITALY 300

数字 100,150,200,300 代表所有国家/地区的每个日期的金额计数。为此，我编写了以下猪脚本。达到了上述预期效果。

data = ORDER table BY date ASC;

data1 = GROUP data BY (date, country);

countof_amount = FOREACH data1 GENERATE
             FLATTEN(group) AS (date, country),
             COUNT(data) AS amount_count;

countof_amount1 = order countof_amount by date ASC;

现在，我想找到所有国家/地区每个日期的所有金额的总和，例如从图表 A，我想要以下结果：

201201 250
201305 240
201403 300

我该怎么做呢？

提前致谢！

Answer 1

添加最后三行它将起作用。我在本地测试过，效果很好。

table = LOAD 'input.txt' using PigStorage(' ') as(amount:long,date:chararray,country:chararray);  
data = ORDER table BY date ASC;  
data1 = GROUP data BY (date,country);  
countof_amount = FOREACH data1 GENERATE 
            FLATTEN(group) AS (date, country),  
           COUNT(data.amount) AS (amount_count);  
countof_amount1 = order countof_amount by date ASC;  

mycount =  group countof_amount1 by date;  
getFinalCount = FOREACH mycount  GENERATE group as date,SUM(countof_amount1.amount_count) as total;  
dump getFinalCount;