hadoop - pig 错误 1066 : Unable to open iterator for alias test

Question

我得到:

org.apache.pig.impl.logicalLayer.FrontendException: ERROR 1066: Unable to open iterator for test

当我有代码时:

my_file = LOAD '$my_records_file' USING PigStorage('\t') AS (field0:chararray, field1:int);
test = FILTER my_file BY field0 != null;

为什么会出现此错误？

Answer 1

我想您想过滤具有空值的行？ 语法是 field0 IS NOT NULL。

my_file = LOAD '$my_records_file' USING PigStorage('\t') AS (field0:chararray, field1:int);
test = FILTER my_file BY field0 IS NOT NULL;

但是如果你想过滤值为空的行，代码是:

my_file = LOAD '$my_records_file' USING PigStorage('\t') AS (field0:chararray, field1:int);
test = FILTER my_file BY field0 !='null';