connecting koa js backend with parcel front

Item Model.js

const mongoose = require("mongoose")
const ItemSchema = new mongoose.Schema({
    itemId: {type:String, required: true},
    itemName : {type: String, required: true},
})
const Item = mongoose.model("items", ItemSchema);
module.exports = Item;

ItemController.js file here you have the apiis

const Item = require("../Models/ItemModel");

add item function in here used itemId and Item Name

const addItem = async(ctx)=>{    
    try {
        const {itemId,itemName} = ctx.request.body;
        const item =await Item.create({
            itemName,
            itemId,
        })
        return (ctx.body = item);
    } catch (error) {
        return (ctx.body ={message : error.message})
    }
}

get item function this means get all items

const getItems = async(ctx)=>{
    try {
        const item = await Item.find();
        return(ctx.body = item)
    } catch (error) {
        return (ctx.body ={message : error.message})
    }
}

delete items function inhere we need to pass the id to identify the specifit item amoung all of them

const deleteItems = async(ctx)=>{
    try {
        const itemid = ctx.params.id;
        const item = await Item.findByIdAndDelete(itemid);
        return (ctx.body = item);
    } catch (error) {
        return (ctx.body ={message : error.message})
    }
}

find by id method in here we get id and find the item bu

const findByIDItems = async(ctx)=>{
    try {
        const itemid = ctx.params.id;
        const item = await Item.findById(itemid)
        return (ctx.body = item);
    } catch (error) {
        return (ctx.body ={message : error.message})
    }
}

update item method in this method we used mongoose to update the query

const updateItem = async(ctx)=>{
    try {
        const {itemName,itemId} = ctx.request.body;
        const itemid = ctx.params.id;
        const item = await Item.findByIdAndUpdate(itemid,{
            itemName,
            itemId,
        })
        return (ctx.body = item)
    } catch (error) {
        return (ctx.body ={message : error.message})
        
    }
}

exporting

module.exports = {addItem,getItems,deleteItems,findByIDItems,updateItem}
   

Router file

  const KoaRouter = require('@koa/router');
  const router = new KoaRouter({prefix:"/items"});
  const {addItem,getItems,deleteItems,findByIDItems,
  updateItem}=require("../Controller/ItemController")

routers and links

router.post("/add",addItem);
router.get("/",getItems);
router.put("/:id",updateItem);
router.get("/:id",findByIDItems);
router.delete("/:id",deleteItems);

exporting the module

module.exports=router;

this is DB connection file you connect DB by this file

const mongoose  = require("mongoose");
const dbConnect = () =>{
    mongoose.connect('mongodb://localhost:27017',()=>{
               console.log("Db connected success")
    })
 }
 module.exports ={dbConnect}

>Solution :

this is server JS file for you

imported methods

const Koa = require('koa')
const KoaRouter = require('@koa/router');
const cors = require('@koa/cors')
const bodyParser = require('koa-bodyparser')
const json = require('koa-json')
const {dbConnect} = require('./Utils/DBconnect');
const itemRouter = require("./Routes/itemRouter");
const app = new Koa();
const router = new KoaRouter();

these are the middlewares

app.use(cors());
app.use(bodyParser());
app.use(json());
app.use(router.routes()).use(router.allowedMethods());
app.use(itemRouter.routes());

in here you listen to the app

app.listen(8000,()=>{
    dbConnect();
    console.log("server running")
    console.log("in 8000")
})