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From "Markus Wiesenbacher | Codefreun.de" ...@codefreun.de>
Subject Re: getFieldValue()
Date Fri, 17 Jun 2011 15:30:00 GMT
One question regarding point 2: Why should we always use Hector, Thrift is not that bad?

Von meinem iPhone gesendet

Am 17.06.2011 um 17:12 schrieb Jonathan Ellis <jbellis@gmail.com>:

> 1. the right way to right that is to just say struct.name, struct.value, etc
> 2. why are you writing raw thrift instead of using Hector?
> 
> On Fri, Jun 17, 2011 at 5:03 AM, Vivek Mishra
> <vivek.mishra@impetus.co.in> wrote:
>> 
>> 
>> 
>> 
>> From: Vivek Mishra
>> Sent: Friday, June 17, 2011 3:25 PM
>> To: user@cassandra.apache.org
>> Subject: getFieldValue()
>> 
>> 
>> 
>> Hi,
>> 
>> I was looking into  getFieldValue method for SuperColumn and SlicePredicate
>> apis.
>> 
>> 
>> 
>> It looks to me slight confusing as underlying APIs are returning Object and
>> developer can only be aware of type of object either by looking into
>> Cassandra code base or by ClassCastException.
>> 
>> 
>> 
>> For example,
>> 
>> 
>> 
>> I need to retrieve column name  and it’s value for a SuperColumnFamily
>> “SuperCli” is:
>> 
>> 
>> 
>> 
>> 
>> List<KeySlice> keySlices = cassndraClient.get_range_slices(new ColumnParent(
>> 
>>                         "SuperCli"), slicePredicate, keyRange,
>> ConsistencyLevel.ONE);
>> 
>>             System.out.println(keySlices.size()
>> 
>>                         + " No. of rows exist for the column family:" +
>> "SuperCli");
>> 
>>             for( KeySlice slice :keySlices)
>> 
>>             {
>> 
>>                   city = "noida";
>> 
>> System.out.println(new String((byte[])
>> (slice.getColumns().get(0).getSuper_column().getFieldValue(org.apache.cassandra.thrift.SuperColumn._Fields.NAME))).toString());
>> 
>>             }
>> 
>> 
>> 
>> 
>> 
>> Am I doing something wrong or such typecasting is must? Shouldn’t we hide
>> this complexity and handle it implicitly in CASSANDRA? Or may be introducing
>> a Helper Class can reduce such amount of code ?
>> 
>> 
>> 
>> 
>> 
>> 
>> 
>> Is it possible to retrieve a specific SuperColumn by specifying it’s value
>> in SliceRange query?
>> 
>> 
>> 
>> I can’t see any method with  such search API and I believe it is a real time
>> scenario.
>> 
>> 
>> 
>> SuperCli is a super column family holding number of dynamic super columns.
>> 
>> 
>> 
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> 
> 
> 
> -- 
> Jonathan Ellis
> Project Chair, Apache Cassandra
> co-founder of DataStax, the source for professional Cassandra support
> http://www.datastax.com

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