disctinctarray #1

distinctarray1

use itemCollection
db.itemCollection.insert({
	"id" : "1",
	"somefield" : "blah",
	"someotherfield" : "meh",
	"notanotherfield" : "feh",
	"items" : ["item0", "item1", "item2", "item2"]
})
db.itemCollection.insert({
	"id" : "2",
	"somefield" : "bleh",
	"someotherfield" : "geh",
	"notanotherfield" : "beh",
	"items" : ["item0", "item1", "item2", "item1", "item0"]
})
db.itemCollection.insert({
	"id" : "3",
	"somefield" : "bluh",
	"someotherfield" : "heh",
	"notanotherfield" : "jeh",
	"items" : ["item0", "item1", "item2", "item3", "item4"]
})

map = function() {
	if (!this.items) {
		return;
	}
	for (index in this.items) {
		emit(this.items[index], 1);
	}
}
reduce = function(key, values) {
	var count = 0;
	for (index in values) {
		count += values[index];
	}
	return count;
}
db.runCommand( { mapreduce : "itemCollection", map : map , reduce : reduce , query : { "id" : "1"} , out : "items" } );
db.items.find().forEach(printjson);


{ "_id" : "item0", "value" : 1 }
{ "_id" : "item1", "value" : 1 }
{ "_id" : "item2", "value" : 2 }