MongoDB Product MapReduce 5

gistfile1.js

map = function map() {
      emit(this.type, {productColors :[this.color]});
}

reduce = function reduce(key, values) {
          var colors  = [];

          var results = { colors:[] };
   
          values.forEach(function(value){
   		value.productColors.forEach(function(colorValue){
   			colors.push(colorValue);
   	         });
          });

  results.colors = colors;

  return results;
}

> db.product.mapReduce(map,reduce,{out:"productMapReduce5"})
{
	"result" : "productMapReduce5",
	"timeMillis" : 6,
	"counts" : {
		"input" : 6,
		"emit" : 6,
		"reduce" : 2,
		"output" : 2
	},
	"ok" : 1,
}

> db.productMapReduce5.find().pretty()
{
	"_id" : "Shirt",
	"value" : {
		"colors" : [
			"Green",
			"Red",
			"Yellow"
		]
	}
}
{
	"_id" : "Sweat Shirt",
	"value" : {
		"colors" : [
			"Black",
			"Blue",
			"Gray"
		]
	}
}