无法从Node.js应用程序接收JSON数据？

Question

The below jQuery ajax method makes a call to node.js application that returns a json formatted data. I did check the console and it returns the json in this format

{ "SQLDB_ASSIGNED": 607, "SQLDB_POOLED":285, "SQLDB_RELEVANT":892, "SQLDB_TOTSERVERS":19}

However, when i try to access the element using the key name i get "undefined" on the console ?

Nodejs

res.send(JSON.stringify(" { \"SQLDB_ASSIGNED\": "+assigned_tot+", \"SQLDB_POOLED\":"+pooled_tot+", \"SQLDB_RELEVANT\":"+relevant_tot+", \"SQLDB_TOTSERVERS\":"+servertotal+"}"));

Jquery Ajax

  $.ajax({
    url: '/currentdata',
    async: false,
    dataType: 'json',
    success: function (data) {

    console.log(data);

    for(var i in data)
         {
        console.log(data[i].SQLDB_ASSIGNED+"---"+data[i].SQLDB_POOLED+"---"+data[i].SQLDB_RELEVANT+"---"+data[i].SQLDB_TOTSERVERS ); 
         }
    }
  });

Answer 1

Your Node.js part is very weird. You are stringifying a string:

res.send(JSON.stringify(" { \"SQLDB_ASSIGNED\": "+assigned_tot+", \"SQLDB_POOLED\":"+pooled_tot+", \"SQLDB_RELEVANT\":"+relevant_tot+", \"SQLDB_TOTSERVERS\":"+servertotal+"}"));

Why not just this? That's probably what you are looking for:

res.send(JSON.stringify({
  SQLDB_ASSIGNED: assigned_tot,
  SQLDB_POOLED: pooled_tot,
  SQLDB_RELEVANT: relevant_tot,
  SQLDB_TOTSERVERS: servertotal
}));

And then in the callback just this:

data.SQLDB_ASSIGNED; // Here you go

Answer 2

I don't know why you are iterating over the keys of the json. You want this:

console.log(data.SQLDB_ASSIGNED+"---"+data.SQLDB_POOLED+"---"+data.SQLDB_RELEVANT+"---"+data.SQLDB_TOTSERVERS );

So the code would be:

$.ajax({
    url: '/currentdata',
    async: false,
    dataType: 'json',
    success: function (data) {

        console.log(data.SQLDB_ASSIGNED+"---"+data.SQLDB_POOLED+"---"+data.SQLDB_RELEVANT+"---"+data.SQLDB_TOTSERVERS );

    }
});

Answer 3

You seem to be treating the data variable as an array of objects, containing the keys you specify. I guess what you would like to do is this:

for(var key in data) {
  console.log(key+": "+data[key]);
}

Or what?