Hi Deepak,
In-line
On Tue, Sep 11, 2012 at 10:16 AM, Deepak Balasubramanyam
<deepak.b...@gmail.com> wrote:
> I was researching the same question and found the answer after some
> tinkering around. You need a JS source function. You must write the JS
> source code for the sort algorithm too.
>
> JSSourceFunction phaseFunction = new JSSourceFunction(
> "function(v) {" +
> "return v.sort(function(a, b) {" +
> "return a.field - b.field ;" +
> "}" +
> ");" +
> "}");
> IndexQuery iq = new BinValueQuery(BinIndex.named("indx_name"),"bucket",
> "value"); // get an index
> MapReduceResult execute = client.mapReduce(iq).addMapPhase(new
> NamedJSFunction("Riak.mapValuesJson"),
> false).addReducePhase(phaseFunction).execute();
> String resultRaw = execute.getResultRaw(); // Raw data
> Collection<YourType> result = execute.getResult(YourType .class); //
> serialized to a domain object
>
> The result of this operation will depend on what you return in your reduce()
> function. The result may be a YourType or YourType[] etc. I wanted to
> mention that since Jackson can complain about serialization issues if you
> return the wrong values.
>
> Anyone know how to get this into a wiki ?
This would probably fit better on the Riak-Java-Client wiki.
https://github.com/basho/riak-java-client/wiki/TODO
There's an open TODO for MapReduce examples and I know Brian would
love some help with it. Care to take a stab at adding that code?
Mark
>
> Thanks
> Deepak Bala
>
> On Wed, Aug 29, 2012 at 5:09 PM, Oved Machlev <omach...@interwise.com>
> wrote:
>>
>> Hi,
>>
>>
>>
>> How can I use the sorting functions over 'real' fields in the stored
>> objects? How can I set the field on which I want to sort by?
>>
>>
>>
>> It seems that the following refers to the key, in my case it's a UUID, and
>> therefore useless to sort by:
>>
>>
>>
>> MapReduceResult result = riakClient.
>>
>> mapReduce("some_bucket").
>>
>> addMapPhase(new
>> NamedJSFunction("Riak.mapValuesJson"), false).
>>
>> addReducePhase(new
>> NamedErlangFunction("riak_kv_mapreduce", "reduce_sort"), true).
>>
>> execute();
>>
>>
>>
>>
>>
>> thanks,
>>
>> Oved.
>>
>>
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>
>
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