Database module for node.js

Question

This will get quite clumsy if I continue down the road with this design, so I'm asking you, enlightened ones, is there a way to make this prettier and easier to understand? Primarily the run-function (Especially in the else if where self.query and self.find are set), also, I want it to be chain-able, with .run being the last function.

db = function(dir){
 if(dir[dir.length - 1] == "/") this.dir = dir.slice(0, -1);
 else this.dir = dir;
 return this;
}
db.prototype.table = function(table){
 this.table = table;
 return this;
}
db.prototype.put = function(obj){
 this.put = obj;
 return this;
}
db.prototype.find = function(query){
 this.query = query;
 this.find = "all";
 return this;
}
db.prototype.pluck = function(){
 this.pluck = arguments;
 return this;
}
db.prototype.run = function(callback){
 var self = JSON.parse(JSON.stringify(this));
 for(var key in this){
 if(typeof this[key] != "function" && key != "dir" && key != "table") delete this[key];
 }
 helper.mkdb(self, function(err, created){
 helper.mktbl(self, function(err, created){ 
 var docs = [];
 if(self.put){
 helper.put(self, function(err, docs){
 callback(err, docs);
 })
 }else if(self.query && self.find){
 helper.find(self, function(err, docs){
 if(err) callback(err);
 else{
 self.docs = docs;
 if(self.pluck){
 helper.pluck(self, function(err, docs){
 callback(err, docs);
 })
 }else{
 callback(err, docs);
 }
 }
 })
 }else if(self.pluck){
 helper.pluck(self, function(err, docs){
 callback(err, docs);
 })
 }else callback(new Error("Cannot execute \".run()\" without any functions before it"));
 })
 });
}

Answer 1

I've found a way, it's not the best though. You can use nimble (Or async, it's basically the same but both larger in size and contain more functions) to do a series of functions, and then check from within the helper-class to see if a certain value has been set.

This is my new and improved version of the run-function:

db.prototype.run = function(callback){
 var self = JSON.parse(JSON.stringify(this));
 for(var key in this){
 if(typeof this[key] != "functions" && key != "dir" && key != "table") delete this[key];
 }
 helper.mkdb(self, function(err, created){
 helper.mktbl(self, function(err, created){ 
 self.docs = [];
 nimble.series([
 function(done){
 if(!self.put) done(err, []);
 else{
 helper.put(self, function(err, docs){
 self.docs = docs;
 done(err, docs);
 })
 }
 },
 function(done){
 if(!self.query && !self.find) done(err, self.docs || []);
 else{
 helper.find(self, function(err, docs){
 self.docs = docs;
 done(err, docs);
 })
 }
 },
 function(done){
 if(!self.pluck) done(err, self.docs || []);
 else{
 helper.pluck(self, function(err, docs){
 self.docs = docs;
 done(err, docs);
 })
 }
 }
 ], function(err, res){
 callback(err, helper.lastData(res));
 })
 })
 });
}