猪 - 无法推断org.apache.pig.piggybank.evaluation.datetime.convert.ISOToUnix的匹配函数为多个或不匹配

Question

我只是试图将猪的日期时间格式转换为纪元时间所以我可以用时间做其他计算。这是我的（部分）脚本如下：

DEFINE ISOToUnix org.apache.pig.piggybank.evaluation.datetime.convert.ISOToUnix(); 
A = LOAD 's3://hearstlogfiles/google/NetworkBackfillImpressions_271283/2014/09/24/NetworkBackfillImpressions_271283_20140924_00.gz' USING PigStorage(','); 
B = LIMIT A 10; 
C = FOREACH B GENERATE 
(chararray)(CONCAT(CONCAT(SUBSTRING($0, 0,10),' '),SUBSTRING($0, 11,19))) as dt_string:chararray, 
DATE_TIME(CONCAT(CONCAT(SUBSTRING($0, 0,10),' '),SUBSTRING($0, 11,19))) AS dt; 
D = FOREACH C GENERATE 
dt_string, 
dt, 
ISOToUnix(dt)/1000 as epoch:long; 
DUMP D; 

当猪试图执行下面的行，我得到它下面的错误。我知道我把dt作为正确的格式。

ISOToUnix(dt)/1000 as epoch:long 
Could not infer the matching function for org.apache.pig.piggybank.evaluation.datetime.convert.ISOToUnix as multiple or none of them fit. Please use an explicit cast. 

当我DUMP C，我得到以下。所以我知道C dt的格式是正确的。

(2014-09-24 02:53:54,2014-09-24T02:53:54.000Z) 
(2014-09-24 02:57:54,2014-09-24T02:57:54.000Z) 
(2014-09-24 03:05:06,2014-09-24T03:05:06.000Z) 
(2014-09-24 03:27:30,2014-09-24T03:27:30.000Z) 
(2014-09-24 03:37:00,2014-09-24T03:37:00.000Z) 
(2014-09-24 03:39:18,2014-09-24T03:39:18.000Z) 
(2014-09-24 03:41:24,2014-09-24T03:41:24.000Z) 
(2014-09-24 03:43:18,2014-09-24T03:43:18.000Z) 
(2014-09-24 03:58:12,2014-09-24T03:58:12.000Z) 

请帮忙。

Answer 1

从 https://pig.apache.org/docs/r0.7.0/api/org/apache/pig/piggybank/evaluation/datetime/convert/ISOToUnix.html

粘贴例如：

REGISTER /Users/me/commiter/piggybank/java/piggybank.jar ; 
REGISTER /Users/me/commiter/piggybank/java/lib/joda-time-1.6.jar ; 
DEFINE ISOToUnix org.apache.pig.piggybank.evaluation.datetime.convert.ISOToUnix(); 
ISOin = LOAD 'test.tsv' USING PigStorage('\t') AS (dt:chararray, dt2:chararray); 

DESCRIBE ISOin; 
ISOin: {dt: chararray,dt2: chararray} 

DUMP ISOin; 
(2009-01-07T01:07:01.000Z,2008-02-01T00:00:00.000Z) 
(2008-02-06T02:06:02.000Z,2008-02-01T00:00:00.000Z) 
(2007-03-05T03:05:03.000Z,2008-02-01T00:00:00.000Z) 
... 

toUnix = FOREACH ISOin GENERATE ISOToUnix(dt) AS unixTime:long; 

DESCRIBE toUnix; 
toUnix: {unixTime: long} 
DUMP toUnix; 
(1231290421000L) 
(1202263562000L) 
(1173063903000L) 
... 

如果你已经注意到，DT（这是为PARAM传递给ISOToUnix UDF是chararray所以，你需要强制转换的“DT”一栏下面chararray：

C = FOREACH B 
     GENERATE 
      (chararray)(CONCAT(CONCAT(SUBSTRING($0, 0,10),' '), 
      SUBSTRING($0, 11,19))) as dt_string:chararray, 
      CONCAT(CONCAT(SUBSTRING($0, 0,10),' '),SUBSTRING($0, 11,19)) AS dt:chararray; 

D = FOREACH C 
     GENERATE 
      dt_string, 
      dt, 
      ISOToUnix((chararray)dt)/1000 as epoch:long; 

DUMP D; 

希望这有助于。