Get data out of map loop - node.js

Question

I'm new to mongodb. And running a query and iterating a loop on it and inside loop I'm fetching data from another query and inserting it into the first one. But when I log the first query data outside the map iteration it does't show the second query data there. Below is my code:-
banner=await Banner.find({teacher:{$nin:exclude_academy},status:1})
.select('id position type type_id link banner amount')
.sort({position:1})
banner.map(async(bann)=>{
var course_data=await Course.findById(bann.type_id).exec();
course_data['type']='course';
bann['data']=course_data;
})
console.log(banner);
When I log the banner data it only shows first query data.
Below is my model structure:-
const mongoose=require('mongoose');
const Schema=mongoose.Schema({
teacher:{type:mongoose.Schema.Types.ObjectId, ref:"User", required:true},
position:{type:Number, default:0},
type:{type:String, required:true},
type_id:mongoose.Schema.Types.ObjectId,
image:{type:String, required:true},
amount:Number,
data:Object,
status:{type:Number, default:0},
data:Object
},
{
timestamps:true
});
module.exports=mongoose.model("Banner",Schema);

Answer 1

Finally, I solved it and here is the answer to the question. I need to call the callback function to get the data. Below is the complete code:-
var banner=await Banner.find({teacher:{$nin:exclude_academy},status:1})
.select('id position type type_id link banner amount')
.sort({position:1})
async function findData(type, type_id) {
var course_data=await Course.findById(type_id).exec();
course_data['type']='course';
course_data['purchase_status']=status;
return course_data;
}
await Promise.all(banner.map(async(bann)=>{
if (bann.type_id!='')
{
const data = await findData(bann.type,bann.type_id);
bann['data']=data;
}
}))
console.log(banner);