豬編程通過使用count（*）在組上使用拆分

Question

輸入文件為：

2, cornflakes, Regular,General Mills, 12
3, cornflakes, Mixed Nuts, Post, 14
4, chocolate syrup, Regular, Hersheys, 5
5, chocolate syrup, No High Fructose, Hersheys, 8
6, chocolate syrup, Regular, Ghirardeli, 6
7, chocolate syrup, Strawberry Flavor, Ghirardeli, 7

filter3 = LOAD 'location_of_file' using PigStorage('\t') as (item_sl : int, item : chararray, type: chararray, manufacturer: chararray, price : int);

SPLIT filter3 INTO filter4 IF (FOREACH (filter3 GROUP BY item) GENERATE group, COUNT(item < 3)), filter6_pass OTHERWISE;

就像對帶有count（*）<3的項進行分組的SQL一樣

所需的輸出是：

4, chocolate syrup, Regular, Hersheys, 5
5, chocolate syrup, No High Fructose, Hersheys, 8
6, chocolate syrup, Regular, Ghirardeli, 6
7, chocolate syrup, Strawberry Flavor, Ghirardeli, 7

Answer 1

按項目分組，獲取計數，然后對計數使用過濾器

A = LOAD 'location_of_file' using PigStorage('\t') as (item_sl : int, item : chararray, type: chararray, manufacturer: chararray, price : int);
B = GROUP A BY item;
C = FOREACH B GENERATE group,COUNT(A.item) AS Total;
D = FILTER C BY Total > 3;
E = JOIN A BY item,D BY $0;
F = FOREACH E GENERATE $0..$4;
DUMP F;