nodejs Multiple Async operations on a collection - node.js

Question

I'm in a process of building a nodejs app and i'm quite new to nodejs asynchronous model.
the problem is that i've modified a database collection to include a string field while sill referencing another collection, namely, I've modified vehicle model to include extra field named make name as string field instead of just referencing the make collection, i've done this de-normalization for the sake of efficiency as this field is frequently read not written.
an excerpt from DB schema :
var vehicleSchema = new mongoose.Schema({
stringId: String,
make: {
type: mongoose.Schema.Types.ObjectId, ref:"Make",
makeText: String
},
and here is an excerpt for make schema:
var makeSchema = new mongoose.Schema({
name: String,
models: [modelSchema]
});
the problem is that i've some data in the collection already, i need to write a code to loop through the vehicles in the vehicle collection and then lookup the vehicle's make id against the makes collection, then find the corresponding make name string and assign that value to vehicle.make.makeText
I done an extensive research and i reached asyn module, below is the code that i wrote to solve this problem:
// code to loop through all records in vehicles collection and add makeText
vehicle.find({},(err,allVehicles) =>{
console.log("executed vehicle.find()");
async.eachOfSeries(allVehicles,function(vehicle){
console.log(vehicle.stringId);
make.findById(vehicle.make.id,function(err,foundMake){
vehicle.make.makeText = foundMake.name;
console.log(foundMake.name);
vehicle.save(function(err,saved){
if(err){
console.log(err.message);
}
})
})
},function(err){
if (err){
console.log(err.message);
}
}
)});
unfortunately the code seem to execute only once and i don't see the effect of vehicle.save method as i can't see the change to the DB.
Thanks in advance

Answer 1

I think you don't use eachOfSeries right http://caolan.github.io/async/docs.html#eachOfSeries
A function to apply to each item in coll. The key is the item's key,
or index in the case of an array. The iteratee is passed a
callback(err) which must be called once it has completed. If no error
has occurred, the callback should be run without arguments or with an
explicit null argument. Invoked with (item, key, callback).
You get a key, not full object, and MUST call a callback.

Answer 2

You forgot the next() function, You need to call it after the findById returns.Did not run this fix, however it shows where the
problem is
> // code to loop through all records in vehicles collection and add
> makeText vehicle.find({},(err,allVehicles) =>{
>
> console.log("executed vehicle.find()");
> async.eachOfSeries(allVehicles,function(vehicle,next){
> console.log(vehicle.stringId);
> make.findById(vehicle.make.id,function(err,foundMake){
> vehicle.make.makeText = foundMake.name;
> console.log(foundMake.name);
> vehicle.save(function(err,saved){
> if(err){
> console.log(err.message);
> next(err)
> }else{
> next();
> }
>
> })
> })
>
> },function(err){
> if (err){
> console.log(err.message);
> }
>
> }
>
> )});