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From Miguel Angel Martin junquera <mianmarjun.mailingl...@gmail.com>
Subject Re: how can i get the column value? Need help!.. cassandra 1.28 and pig 0.11.1
Date Fri, 30 Aug 2013 08:01:42 GMT
I try this:

*rows = LOAD
'cql://keyspace1/test?page_size=1&split_size=4&where_clause=age%3D30' USING
CqlStorage();*

*dump rows;*

*ILLUSTRATE rows;*

*describe rows;*

*
*

*values2= FOREACH rows GENERATE  TOTUPLE (id) as
(mycolumn:tuple(name,value));*

*dump values2;*

*describe values2;*
*
*

But I get this results:



-------------------------------------------------------------
| rows     | id:chararray   | age:int   | title:chararray   |
-------------------------------------------------------------
|          | (id, 6)        | (age, 30) | (title, QA)       |
-------------------------------------------------------------

rows: {id: chararray,age: int,title: chararray}
2013-08-30 09:54:37,831 [main] ERROR org.apache.pig.tools.grunt.Grunt -
ERROR 1031: Incompatable field schema: left is
"tuple_0:tuple(mycolumn:tuple(name:bytearray,value:bytearray))", right is
"org.apache.pig.builtin.totuple_id_1:tuple(id:chararray)"





or



....

*values2= FOREACH rows GENERATE  TOTUPLE (id) ;*
*dump values2;*
*describe values2;*




and  the results are:


...
(((id,6)))
(((id,5)))
values2: {org.apache.pig.builtin.totuple_id_8: (id: chararray)}



Aggg!!!!!


*
*




Miguel Angel Martín Junquera
Analyst Engineer.
miguelangel.martin@brainsins.com



2013/8/28 Miguel Angel Martin junquera <mianmarjun.mailinglist@gmail.com>

> hi:
>
> I can not understand why the schema is  define like *"id:chararray,age:int,title:chararray"
>  and it does not define like tuples or bag tuples,  if we have pair
> key-values  columns*
> *
> *
> *
> *
> *I try other time to change schema  but it does not work.*
> *
> *
> *any ideas ...*
> *
> *
> *perhaps, is the issue in the definition cql3 tables ?*
> *
> *
> *regards*
>
>
> 2013/8/28 Miguel Angel Martin junquera <mianmarjun.mailinglist@gmail.com>
>
>> hi all:
>>
>>
>> Regards
>>
>> Still i can resolve this issue. .....
>>
>> does anybody have this issue or try to test this simple example?
>>
>>
>> i am stumped I can not find a solution working.
>>
>> I appreciate any comment or help
>>
>>
>> 2013/8/22 Miguel Angel Martin junquera <mianmarjun.mailinglist@gmail.com>
>>
>>> hi all:
>>>
>>>
>>>
>>>
>>> I,m testing the new CqlStorage() with cassandra 1.28 and pig 0.11.1
>>>
>>>
>>> I am using this sample data test:
>>>
>>>
>>> http://frommyworkshop.blogspot.com.es/2013/07/hadoop-map-reduce-with-cassandra.html
>>>
>>> And I load and dump data Righ with this script:
>>>
>>> *rows = LOAD
>>> 'cql://keyspace1/test?page_size=1&split_size=4&where_clause=age%3D30'
USING
>>> CqlStorage();*
>>> *
>>> *
>>> *dump rows;*
>>> *describe rows;*
>>> *
>>> *
>>>
>>> *resutls:
>>>
>>> ((id,6),(age,30),(title,QA))
>>>
>>> ((id,5),(age,30),(title,QA))
>>>
>>> rows: {id: chararray,age: int,title: chararray}
>>>
>>>
>>> *
>>>
>>>
>>> But i can not  get  the column values
>>>
>>> I try to define   another schemas in Load like I used with
>>> cassandraStorage()
>>>
>>>
>>> http://cassandra-user-incubator-apache-org.3065146.n2.nabble.com/Cassandra-and-Pig-how-to-get-column-values-td5641158.html
>>>
>>>
>>> example:
>>>
>>> *rows = LOAD
>>> 'cql://keyspace1/test?page_size=1&split_size=4&where_clause=age%3D30'
USING
>>> CqlStorage() AS (columns: bag {T: tuple(name, value)});*
>>>
>>>
>>> and I get this error:
>>>
>>> *2013-08-22 12:24:45,426 [main] ERROR org.apache.pig.tools.grunt.Grunt
>>> - ERROR 1031: Incompatable schema: left is
>>> "columns:bag{T:tuple(name:bytearray,value:bytearray)}", right is
>>> "id:chararray,age:int,title:chararray"*
>>>
>>>
>>>
>>>
>>> I try to use, FLATTEN, SUBSTRING, SPLIT UDF`s but i have not get good
>>> result:
>>>
>>> Example:
>>>
>>>
>>>    - when I flatten , I get a set of tuples like
>>>
>>> *(title,QA)*
>>>
>>> *(title,QA)*
>>>
>>> *2013-08-22 12:42:20,673 [main] INFO
>>>  org.apache.pig.backend.hadoop.executionengine.util.MapRedUtil - Total
>>> input paths to process : 1*
>>>
>>> *A: {title: chararray}*
>>>
>>>
>>>
>>> but i can get value QA
>>>
>>> Sustring only works with title
>>>
>>>
>>>
>>> example:
>>>
>>> *B = FOREACH A GENERATE SUBSTRING(title,2,5);*
>>> *
>>> *
>>> *dump B;*
>>> *describe B;*
>>> *
>>> *
>>> *
>>> *
>>>
>>> *results:*
>>> *
>>> *
>>>
>>> *(tle)*
>>> *(tle)*
>>> *B: {chararray}*
>>>
>>>
>>>
>>>
>>> i try, this like ERIC LEE inthe other mail  and have the same results:
>>>
>>>
>>>  Anyways, what I really what is the column value, not the name. Is there
>>> a way to do that? I listed all of the failed attempts I made below.
>>>
>>>    - colnames = FOREACH cols GENERATE $1 and was told $1 was out of
>>>    bounds.
>>>    - casted = FOREACH cols GENERATE (tuple(chararray, chararray))$0;
>>>    but all I got back were empty tuples
>>>    - values = FOREACH cols GENERATE $0.$1; but I got an error telling
>>>    me data byte array can't be casted to tuple
>>>
>>>
>>> Please, I will appreciate any help
>>>
>>>
>>> Regards
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>
>>
>> --
>>
>> Miguel Angel Martín Junquera
>> Analyst Engineer.
>> miguelangel.martin@brainsins.com
>> Tel. / Fax: (+34) 91 485 56 66
>> *http://www.brainsins.com*
>> Smart eCommerce
>> *Madrid*: http://goo.gl/4B5kv
>>  *London*: http://goo.gl/uIXdv
>>  *Barcelona*: http://goo.gl/NZslW
>>
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>> La legislación española ampara el secreto de las comunicaciones. Este
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>>
>
>
>
> --
>
> Miguel Angel Martín Junquera
> Analyst Engineer.
> miguelangel.martin@brainsins.com
>
>

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