How to Group By and Sum

How to Group By and Sum?

Source: StackOverflow.com

Question

There is a JSON like this:

[
  {
     platformId: 1,
     payout: 15,
     numOfPeople: 4
  },
  {
     platformId: 1,
     payout: 12,
     numOfPeople: 3

  },
  {
     platformId: 2,
     payout: 6,
     numOfPeople: 5

  },
  {
     platformId: 2,
     payout: 10,
     numOfPeople: 1
  },

]

And I want to Group it by platformId with sum of payout and numOfPeople. I.e. in result I want JSON like this:

[
  "1": {
     payout: 27,
     numOfPeople: 7
   },

  "2": {
     payout: 16,
     numOfPeople: 6
  }
] 

Answer

    var res = alasql('SELECT INDEX platformId, {platformId:platformId, numOfPeople:numOfPeople} \
         FROM (SELECT platformId, SUM(payout) AS payout, SUM(numOfPeople) AS numOfPeople \
             FROM ? GROUP BY platformId)',[data]);

Try this example at jsFiddle