Question

所以，我有一个数据有两个值，字符串和数字。

data(string:chararray, number:int)

我正在计算5个不同的规则，

1：int为0~1。

2：int为1~2。

〜

5：int为4~5。

所以我能够单独计算它们，

zero_to_one = filter avg_user by average_stars >= 0 and average_stars <= 1;
A = GROUP zero_to_one ALL;
zto_count = FOREACH A GENERATE COUNT(zero_to_one);

one_to_two = filter avg_user by average_stars > 1 and average_stars <= 2;
B = GROUP one_to_two ALL;
ott_count = FOREACH B GENERATE COUNT(one_to_two);

two_to_three = filter avg_user by average_stars > 2 and average_stars <= 3;
C = GROUP two_to_three ALL;
ttt_count = FOREACH C GENERATE COUNT( two_to_three);

three_to_four = filter avg_user by average_stars > 3 and average_stars <= 4;
D = GROUP three_to_four ALL;
ttf_count = FOREACH D GENERATE COUNT( three_to_four);

four_to_five = filter avg_user by average_stars > 4 and average_stars <= 5;
E = GROUP four_to_five ALL;
ftf_count = FOREACH E GENERATE COUNT( four_to_five);

所以，这可以做到，但是这只会产生5个单独的表。

我想知道是否有任何方式（可以想象，我喜欢花哨的东西） T可以在单个表中生成结果。

这意味着

zto_count = 1
ott_count = 3
. = 2
. = 3
. = 5

然后表格为{1,3,2,3,5}

解析数据并以这种方式组织它们很容易。

有什么方法吗？

Answer 1

将此作为输入：

foo 2
foo 3
foo 2
foo 3
foo 5
foo 4
foo 0
foo 4
foo 4
foo 5
foo 1
foo 5

（0和1每个出现一次，2和3每次出现两次，4和5每次出现三次）

这个脚本：

A = LOAD 'myData' USING PigStorage(' ') AS (name: chararray, number: int);

B = FOREACH (GROUP A BY number) GENERATE group AS number, COUNT(A) AS count ;

C = FOREACH (GROUP B ALL) {
    zto = FOREACH B GENERATE (number==0?count:0) + (number==1?count:0) ;
    ott = FOREACH B GENERATE (number==1?count:0) + (number==2?count:0) ;
    ttt = FOREACH B GENERATE (number==2?count:0) + (number==3?count:0) ;
    ttf = FOREACH B GENERATE (number==3?count:0) + (number==4?count:0) ;
    ftf = FOREACH B GENERATE (number==4?count:0) + (number==5?count:0) ;
    GENERATE SUM(zto) AS zto,
             SUM(ott) AS ott,
             SUM(ttt) AS ttt,
             SUM(ttf) AS ttf,
             SUM(ftf) AS ftf ;
}

生成此输出：

C: {zto: long,ott: long,ttt: long,ttf: long,ftf: long}
(2,3,4,5,6)

C中FOREACH的数量应该不重要，因为C最多只有5个元素，但如果是，那么它们可以像这样放在一起：

C = FOREACH (GROUP B ALL) {
    total = FOREACH B GENERATE (number==0?count:0) + (number==1?count:0) AS zto,
                               (number==1?count:0) + (number==2?count:0) AS ott,
                               (number==2?count:0) + (number==3?count:0) AS ttt,
                               (number==3?count:0) + (number==4?count:0) AS ttf,
                               (number==4?count:0) + (number==5?count:0) AS ftf ;
    GENERATE SUM(total.zto) AS zto,
             SUM(total.ott) AS ott,
             SUM(total.ttt) AS ttt,
             SUM(total.ttf) AS ttf,
             SUM(total.ftf) AS ftf ;
}

（hadoop.pig）单个表中的多个计数

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