PIG 中的输出格式问题

Question

这是我用PIG写的代码。我想打印如下输出：

John, 3.850000023841858
Mary, 3.925000011920929

而不是下面的输出

DUMP C;
    ({(John),(John),(John),(John)},3.850000023841858)
    ({(Mary),(Mary),(Mary),(Mary)},3.925000011920929)

A = LOAD 'student.txt' AS (name:chararray, term:chararray, gpa:float);

DUMP A;
(John,fl,3.9F)
(John,wt,3.7F)
(John,sp,4.0F)
(John,sm,3.8F)
(Mary,fl,3.8F)
(Mary,wt,3.9F)
(Mary,sp,4.0F)
(Mary,sm,4.0F)

B = GROUP A BY name;

DUMP B;
(John,{(John,fl,3.9F),(John,wt,3.7F),(John,sp,4.0F),(John,sm,3.8F)})
(Mary,{(Mary,fl,3.8F),(Mary,wt,3.9F),(Mary,sp,4.0F),(Mary,sm,4.0F)})

C = FOREACH B GENERATE A.name, AVG(A.gpa);

DUMP C;
({(John),(John),(John),(John)},3.850000023841858)
({(Mary),(Mary),(Mary),(Mary)},3.925000011920929)

Answer 1

而不是 A.name 使用 group

C = FOREACH B GENERATE group, AVG(A.gpa);

PIG 中的输出格式问题

Issue with output format in PIG

hadoop

apache-pig