Filter 清管器10过滤器特征不为空，不为'；行不通

我是新来的猪，我正在玩它，来到一个路障

假设我有以下几点：

dump test;

(1,2014-04-08 12:09:23.0)
(2,2014-04-08 12:09:23.0)
(3,null)
(4,null)

我想过滤“test”以删除空值，所以我会这样做：

filter_test = filter test by test.column2 is not null;

(1,2014-04-08 12:09:23.0)
(2,2014-04-08 12:09:23.0)

给我这样的东西：

filter_test = filter test by test.column2 is not null;

(1,2014-04-08 12:09:23.0)
(2,2014-04-08 12:09:23.0)

但它返回相同的东西。它不会删除空行

我使用的是Pig 10，日期列是Charray类型

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谢谢您的帮助。

您的column2没有空值，这是一个字符。请参见实空值和空为字符的示例

示例1:null作为字符
input.txt

1,2014-04-08 12:09:23.0
2,2014-04-08 12:09:23.0
3,null
4,null

清管器：

A = LOAD 'input.txt' USING PigStorage(',') AS (f1:int,f2:chararray);
B = FILTER A BY f2!='null';
DUMP B;

(1,2014-04-08 12:09:23.0)
(2,2014-04-08 12:09:23.0)

A = LOAD 'input.txt' USING PigStorage(',') AS (f1:int,f2:chararray);
B = FILTER A BY f2 is not null;
DUMP B;

(1,2014-04-08 12:09:23.0)
(2,2014-04-08 12:09:23.0)

输出：

A = LOAD 'input.txt' USING PigStorage(',') AS (f1:int,f2:chararray);
B = FILTER A BY f2!='null';
DUMP B;

(1,2014-04-08 12:09:23.0)
(2,2014-04-08 12:09:23.0)

A = LOAD 'input.txt' USING PigStorage(',') AS (f1:int,f2:chararray);
B = FILTER A BY f2 is not null;
DUMP B;

(1,2014-04-08 12:09:23.0)
(2,2014-04-08 12:09:23.0)

示例2：实际空值
input.txt

1,2014-04-08 12:09:23.0
2,2014-04-08 12:09:23.0
3,
4,

清管器：

A = LOAD 'input.txt' USING PigStorage(',') AS (f1:int,f2:chararray);
B = FILTER A BY f2!='null';
DUMP B;

(1,2014-04-08 12:09:23.0)
(2,2014-04-08 12:09:23.0)

A = LOAD 'input.txt' USING PigStorage(',') AS (f1:int,f2:chararray);
B = FILTER A BY f2 is not null;
DUMP B;

(1,2014-04-08 12:09:23.0)
(2,2014-04-08 12:09:23.0)

输出：

A = LOAD 'input.txt' USING PigStorage(',') AS (f1:int,f2:chararray);
B = FILTER A BY f2!='null';
DUMP B;

(1,2014-04-08 12:09:23.0)
(2,2014-04-08 12:09:23.0)

A = LOAD 'input.txt' USING PigStorage(',') AS (f1:int,f2:chararray);
B = FILTER A BY f2 is not null;
DUMP B;

(1,2014-04-08 12:09:23.0)
(2,2014-04-08 12:09:23.0)

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令人惊叹的！成功了！我看到NULL将是一个空包/元组，我真的认为我尝试了你的方法。我想我没有。谢谢