first_edits.js

var fs = require('fs');
var moment = require('moment');
var sqlite3 = require('sqlite3').verbose();
var db = new sqlite3.Database('sometime.sqlite');

var day = moment("01-01-2012", "MM-DD-YYYY");
var last = moment("02-01-2012", "MM-DD-YYYY");
var end = moment("01-01-2013", "MM-DD-YYYY");

var allusers = {};

db.all(('select distinct(user_id) as u '+
   'FROM osm_changeset WHERE '+
   'closed_at < {start}')
    .replace(/{start}/g, day.unix())
    .replace(/{end}/g, last.unix()),
function(err, rows) {
    for (var i = 0; i < rows.length; i++) {
        allusers[rows[i].u] = true;
    }
    console.log('unique users who edited before 01-01-2012: ' + Object.keys(allusers).length);
    run();
});

function run() {
    if (last.unix() > end.unix()) {
        return;
    }

    db.all(('select distinct(user_id) as u '+
           'FROM osm_changeset WHERE '+
           'closed_at > {start} '+
           'AND closed_at < {end}')
            .replace(/{start}/g, day.unix())
            .replace(/{end}/g, last.unix()),

    function(err, rows) {
        var added = 0;
        for (var i = 0; i < rows.length; i++) {
            if (!allusers[rows[i].u]) added++;
            allusers[rows[i].u] = true;
        }
        console.log('users added in ' + day.format("MMM YY") + ': ' + added);
        day.add('months', 1);
        last.add('months', 1);
        run();
    });

}