Object.keys returns constructor[property]

I'm working with node.js and sqlite on a little tool that will insert data into the database. The problems start because I don't want to know what the data is.

The data constructor will be similar to this

EventFormData = function(){
  this.table = 'event';
  this.eventID = 0;
  this.title = $('#Title').val();
  this.Start_Date = $('#StartDate').val();
  this.Start_Time = $('#StartTime').val();
  this.End_Date = $('#EndDate').val();
  this.End_Time = $('#EndTime').val();
  this.Location = $('#Place').val();
  this.Notes = $('#Notes').val();
};

So every form I make the only code I need to add would be the data constructor for this form, This constructor is global because it is in a jade file and i need it else where.

Now the dbtools.js is as followed:

dbtools = (function () {
  var InsertData = function(data){
    database.serialize(function(){
      var dataArray = [];
      var valueString = "", typeString = "";
      for(var i = 2; i < Object.keys(data).length; i++){
        if(i < Object.keys(data).length-1){
          valueString += "?, ";
        }else{
          valueString += "?";
        }
      }
      console.log(Object.keys(data));

      database.all("INSERT into event ("+Object.keys(data)+") values("+valueString+" )", dataArray);
    });
  };
  return {
    InsertData: InsertData
  };
})();

module.exports = dbtools;

I would imagine this would work but the Object.keys(data) doesn't work right. it returns:

eventFormData[table]
eventFormData[eventID]
...etc.

Now by my understanding in this case Object.keys(data) should return:

table
eventID
...etc.

If I do the same call but the constructor is in the same file it does what I want.

EDIT I call dbtools.InsertData(data); wherever I require dbtools, (mainly in router.post calls)

What am I doing wrong here?