COUNT猪

Question

后加入和GROUP BY我在新的猪，并试图理解为什么我不能指望后加入和组：

A = LOAD 'mary' as (line); 
B = LOAD 'mary' as (line); 

wordsA = foreach A generate flatten(TOKENIZE(line)) as wordA; 
grpdA = group wordsA by wordA; 
cntdA = foreach grpdA generate group, COUNT(wordsA); 

wordsB = foreach B generate flatten(TOKENIZE(line)) as wordB; 
grpdB = group wordsB by wordB; 
cntdB = foreach grpdB generate group, COUNT(wordsB), 'some text'; 

fltB = FILTER cntdB BY $1>1; 

jnd = join cntdA by $1, fltB by $1; 
jnd_n = foreach jnd generate $0; 
grp = group jnd by $0; 
out = foreach grp generate group, count(jnd_n); 

dump jnd_n; 
dump grp; 

转储jnd_n：

(was) 
(was) 
(was) 
(lamb) 
(lamb) 
(lamb) 
(Mary) 
(Mary) 
(Mary) 

转储GRP ：

(was,{(was,2,was,2,some text),(was,2,Mary,2,some text),(was,2,lamb,2,some text)}) 
(Mary,{(Mary,2,was,2,some text),(Mary,2,Mary,2,some text),(Mary,2,lamb,2,some text)}) 
(lamb,{(lamb,2,was,2,some text),(lamb,2,Mary,2,some text),(lamb,2,lamb,2,some text)}) 

但我发现了错误：

Invalid scalar projection: jnd_n : A column needs to be projected from a relation for it to be used as a scalar

如果我试图改变代码：

out = foreach grp generate group, count(jnd_n.$0); 

然后我发现了另一个错误：

Failed to generate logical plan. Nested exception: org.apache.pig.backend.executionengine.ExecException: ERROR 1070: Could not resolve count using imports: [, java.lang., org.apache.pig.builtin., org.apache.pig.impl.builtin.]

我知道我能做到这一点的另一种方式，但我想导致像这正是后做了两次猪手术后JOIN和GROUP BY：

转储：

(was,3) 
(lamb,3) 
(Mary,3) 

Answer 1

COUNT需要在帽。 COUNT是一个关键字。

out = foreach grp generate group, COUNT(jnd_n.$0);`