Pig中跨列的字段总和

Question

我有以下测试数据。

A   B   C

M   O

M   M   M

M   M   M

N       O

P       N

我还想得到每个值的计数，例如 M=7、N=2、O=2、P=1。，其中 A、B 和 C 是列标题。我写了下面的代码。

 test=  LOAD 'testdata' USING PigStorage(',') as(A:chararray,B:chararray,C:chararray); 
 values = FOREACH test GENERATE A==''?'null':(A is null?'null':A)) as A,(B==''?'null':(B is null?'null':B)) as B,(C==''?'null':(C is null?'null':C)) as C;  
 grp = GROUP values ALL;  
 A = FOREACH grp {
 B =FILTER test.A=='M' OR test.B=='M' OR test.C=='M';
 C =FILTER test.A=='N' OR test.B=='N' OR test.C=='N';
 D =FILTER test.A=='O' OR test.B=='O' OR test.C=='O';
 E =FILTER test.A=='P' OR test.B=='P' OR test.C=='P';
 GENERATE group, COUNT(B), COUNT(C),COUNT(D),COUNT(E);
  };

我遇到错误 "Scalar has more than one row in the output"。任何输入都会有所帮助！！

Answer 1

将数据加载为一行，标记字段然后计数

A = load 'testdata' as (line:chararray);
B = foreach A generate flatten(TOKENIZE((chararray)line)) as word;
C = group B by word;
D = foreach C generate group,COUNT(B);
DUMP D;

Pig中跨列的字段总和

Sum of fields across column in Pig

apache-pig