JavaScript SUM and GROUP BY of JSON data

Question

This is my first attempt at doing JavaScript with some JSON data objects and need some advice on the proper way to attain my goal.

Some server-side code actually gen

Answer 1

If you go the LINQ.js route, you can do it like this:

var aggregatedObject = Enumerable.From(dataArray)
        .GroupBy("$.category", null,
                 function (key, g) {
                     return {
                       category: key,
                       hits: g.Sum("$.hits"),
                       bytes: g.Sum("$.bytes")
                     }
        })
        .ToArray();

Working demo with Stack Snippets:

var dataArray = [ 
  { category: "Search Engines", hits: 5, bytes: 50189 },
  { category: "Content Server", hits: 1, bytes: 17308 },
  { category: "Content Server", hits: 1, bytes: 47412 },
  { category: "Search Engines", hits: 1, bytes: 7601  },
  { category: "Business",       hits: 1, bytes: 2847  },
  { category: "Content Server", hits: 1, bytes: 24210 },
  { category: "Internet ",      hits: 1, bytes: 3690  },
  { category: "Search Engines", hits: 6, bytes: 613036 },
  { category: "Search Engines", hits: 1, bytes: 2858  } 
];

var aggregatedObject = Enumerable.From(dataArray)
        .GroupBy("$.category", null,
                 function (key, g) {
                     return {
                       category: key,
                       hits: g.Sum("$.hits"),
                       bytes: g.Sum("$.bytes")
                     }
        })
        .ToArray();

console.log(aggregatedObject);

<script src="//cdnjs.cloudflare.com/ajax/libs/linq.js/2.2.0.2/linq.min.js"></script>

Also, you can find more info on linqjs group by with a sum

Answer 2

Given the dataString above, the below code seems to work. It goes through each object; if the category exists in the groupedObjects array, its hits and bytes are added to the existing object. Otherwise, it is considered new and added to the groupedObjects array.

This solution makes use of underscore.js and jQuery

Here's a jsfiddle demo: http://jsfiddle.net/R3p4c/2/

var objects = $.parseJSON(dataString);
var categories = new Array();
var groupedObjects = new Array();
var i = 0;

_.each(objects,function(obj){
    var existingObj;
    if($.inArray(obj.category,categories) >= 0) {
        existingObj = _.find(objects,function(o){return o.category === obj.category; });
        existingObj.hits += obj.hits;
        existingObj.bytes += obj.bytes;
    } else {
        groupedObjects[i] = obj;
        categories[i] = obj.category;
        i++;
  }
});

groupedObjects = _.sortBy(groupedObjects,function(obj){ return obj.bytes; }).reverse();

Answer 3

Hi here is one solution written by me Visit: aggregate_groupby_js on npm or in aggregate_groupby_js on github

The javascript library for using aggregate functions on array of objects. Basic functions like SUM, MIN, MAX, AVG, DISTINCT_COUNT for entire javascript objects

Example:

var arr = [{`"shape"`:`"square"`,`"color"`:`"red"`,`"used"`:1,`"instances"`:1},
    {`"shape"`:`"square"`,`"color"`:`"red"`,`"used"`:2,`"instances"`:1},
    {`"shape"`:`"circle"`,`"color"`:`"blue"`,`"used"`:0,`"instances"`:0},
    {`"shape"`:`"square"`,`"color"`:`"blue"`,`"used"`:4,`"instances"`:4},
    {`"shape"`:`"circle"`,`"color"`:`"red"`,"`used"`:1,`"instances"`:1},
    {`"shape"`:`"circle"`,`"color"`:`"red"`,`"used"`:1,`"instances"`:0},
    {`"shape"`:`"square"`,`"color"`:`"blue"`,`"used"`:4,`"instances"`:5}, 
    {`"shape"`:`"square"`,`"color"`:`"red"`,`"used"`:2,`"instances"`:1}];

// Specify columns
    var columns =[`"used"`, `"instances"`];

// Initialize object
    var gb = new GroupBy(arr,columns);
// or
    var gb = new GroupBy(arr,[`"used"`, `"instances"`]);

// Call the aggregate functions    
    gb.sum();
    gb.min();
    gb.max();
    gb.avg();
    gb.distinctCount();

Answer 4

var obj = [{Poz:'F1',Cap:10},{Poz:'F1',Cap:5},{Poz:'F1',Cap:5},{Poz:'F2',Cap:20},{Poz:'F1',Cap:5},{Poz:'F1',Cap:15},{Poz:'F2',Cap:5},{Poz:'F3',Cap:5},{Poz:'F4',Cap:5},{Poz:'F1',Cap:5}];
Array.prototype.sumUnic = function(name, sumName){
    var returnArr = [];
    var obj = this;
    for(var x = 0; x<obj.length; x++){
        if((function(source){
            if(returnArr.length == 0){
                return true;
            }else{
                for(var y = 0; y<returnArr.length; y++){
                    var isThere = [];
                    if(returnArr[y][name] == source[name]){
                        returnArr[y][sumName] = parseInt(returnArr[y][sumName]) + parseInt(source[sumName]);
                        return false;
                    }else{
                        isThere.push(source);
                    }
                }
                if(isThere.length>0)returnArr.push(source);
                return false;
            }
        })(obj[x])){
            returnArr.push(obj[x]);
        }
    }
    return returnArr;
}
obj.sumUnic('Poz','Cap');
// return "[{"Poz":"F1","Cap":45},{"Poz":"F2","Cap":25},{"Poz":"F3","Cap":5},{"Poz":"F4","Cap":5}]"

Answer 5

You can use the native functions .reduce() to aggregrate the data, and then .sort() to sort by bytes.

var result = dataObject.reduce(function(res, obj) {
    if (!(obj.category in res))
        res.__array.push(res[obj.category] = obj);
    else {
        res[obj.category].hits += obj.hits;
        res[obj.category].bytes += obj.bytes;
    }
    return res;
}, {__array:[]}).__array
                .sort(function(a,b) { return b.bytes - a.bytes; });

If you're supporting older implementations, you'll need to use a shim for .reduce().