how to distinct in couchbase

Question

I want to create a view in cb that will show some data based on date-range input.

My question is how can I distinct field from the data? Here is my map code:

function (doc, meta) {
  if(!doc.clipGeneration.fromCache){
    var eiid = doc.clipGeneration.batchId;
    if (eiid == null){
        eiid = "API";
    }
    if (  !(doc.clipGeneration.externalId.indexOf("API_INTERVAL_TEST")>=0) )   {
    emit([doc.clipGeneration.clipStyle, eiid,doc.eventOccurenceTimeStamp[0], doc.eventOccurenceTimeStamp[1], doc.eventOccurenceTimeStamp[2],doc.eventOccurenceTimeStamp[3]], doc.insertRawTimestamp);
        emit([doc.clipGeneration.clipStyle, "ALL",doc.eventOccurenceTimeStamp[0], doc.eventOccurenceTimeStamp[1], doc.eventOccurenceTimeStamp[2],doc.eventOccurenceTimeStamp[3]], doc.insertRawTimestamp);
    emit([doc.eventOccurenceTimeStamp[0], doc.eventOccurenceTimeStamp[1], doc.eventOccurenceTimeStamp[2],doc.clipGeneration.clipStyle], doc.insertRawTimestamp);
    }
  }
}

The reduce is _count, and the filters for example are:

startkey: [2015,1,1,null]

endkey: [2015,1,31,"\uffff"]

The output is as expected by the date-range:

{"key":[2015,1,11,"5001188"],"value":1},
{"key":[2015,1,12,"100022"],"value":5},
{"key":[2015,1,12,"155"],"value":11},
{"key":[2015,1,13,"100022"],"value":9},
{"key":[2015,1,13,"155"],"value":6},
{"key":[2015,1,13,"5001159"],"value":1},
{"key":[2015,1,13,"5001190"],"value":3},
{"key":[2015,1,14,"100022"],"value":12},
{"key":[2015,1,14,"5001194"],"value":1},
{"key":[2015,1,15,"100022"],"value":11},
{"key":[2015,1,16,"100022"],"value":10},
{"key":[2015,1,18,"100022"],"value":8},
{"key":[2015,1,18,"5001096"],"value":6},
{"key":[2015,1,18,"5001194"],"value":3}

But as you can see "100022" repeat many times, how can I make somthing like distinct in sql, so it will be shown only once?

Thanks

score 0 · Answer 1 · answered Apr 21 '15 at 14:09

There is no way to actually make ONLY the ID field distrinct. You can reduce by key, but only the whole key - so [date, id] in your case. You can do this in N1QL, because it has an actual DISTINCT keyword just like SQL, but that's still in developer preview at the moment.

how to distinct in couchbase

1 Answers1