Deno — CRUD using mongodb

Hello friends, hope you are doing well. Today we will see how our little Deno connect with DB. So it will be a very very interesting topic for you. Those are not checked our my earlier post about Deno just have it once…

DENO — A First Look

REST API using DENO

Well, so all set, build a CRUD application using Deno.

We will start from where we were at the last topic, I know you are very smart and checked my last topic. We already have an application where we build a REST API. Now its time to introduce DB so things will be in a complete shape. Here to make the thing simple we first connect a mongodb database.

So, we have already seen the app.ts it will be almost same with a little change. See below…

import { Application } from 'https://deno.land/x/oak/mod.ts'; 
import router from './router.ts'; 
const PORT = 8000; 
const app = new Application(); 
app.use(router.routes()); 
app.use(router.allowedMethods()); 
console.log("Server is up and running in port:", PORT); app.listen({port: PORT});

Now, in router.ts we have declare all routing options.

import { Router } from 'https://deno.land/x/oak/mod.ts'; 
import { getEmployees, getEmployee, addEmployee, updateEmployee, deleteEmployee } from './controller.ts'; 
const router = new Router(); 
router 
    .get('/employees', getEmployees) 
    .get('/employee/:empId', getEmployee) 
    .post('/employee', addEmployee) 
    .put('/employee/:empId', updateEmployee)    
    .delete('/employee/:empId', deleteEmployee); 
export default router;

Lastly we have to prepare the controller.ts. See the below code.

import db from "./mongodb.ts"; 
const empCollection = db.collection("employees"); 
const getEmployees = async ({ response }: { response: any }) => {    
    const employees = await empCollection.find(); 
    response.body = employees 
}; 
const getEmployee = async ({ params, response }: { params: { empId: string }; response: any }) => { 
    const employee = await empCollection.findOne({ empId: params.empId }); 
    if (employee) { 
        response.status = 200 
        response.body = employee  
    } else { 
        response.status = 404 
        response.body = { message: 'Employee not found.' } 
    } 
}; 
const addEmployee = async ({ request, response }: { request: any; response: any }) => { 
    const body = request.body(); 
    const emp_val = await body.value; 
    const empId = emp_val.empId; \
    const deptName = emp_val.deptName; 
    const designation = emp_val.designation; 
    const employee: any = { empId, deptName, designation}; 
    const newEmpId = await empCollection.insertOne(employee); 
    response.body = { message: 'OK', data: newEmpId } 
    response.status = 201 
}; 
const updateEmployee = async ({ params, request, response }: { params: { empId: string }; request: any; response: any }) => { 
    const employee = await empCollection.findOne({ empId: params.empId }); 
    if (employee) { 
        const body = request.body(); 
        const emp_val = await body.value; 
        const deptName = emp_val.deptName; 
        const designation = emp_val.designation; 
        const { modifiedCount } = await empCollection.updateOne( 
        {empId: params.empId }, { $set: {deptName, designation }
        }); 
        if (modifiedCount) { 
            response.status = 200 
            const newEmployee = await empCollection.findOne({ empId: params.empId }); 
            response.body = { message: 'OK', data: newEmployee } 
        } else { 
            response.status = 404 
            response.body = { message: `Employee not found` } 
        } 
    } 
}; 
const deleteEmployee = async ({ params, response }: { params: { empId: string }; response: any }) => { 
    const count = await empCollection.deleteOne({ empId: params.empId }); 
    if (!count) { 
        response.status = 404; 
        response.body = { message: "Note does not exist" }; 
    } else { 
        response.body = { message: 'OK' } 
        response.status = 200 
    } 
}; 
export { getEmployees, getEmployee, addEmployee, updateEmployee, deleteEmployee }

Now we have to prepare the mongodb.ts here we need to first impor the MongoClient from Deno’s library.

import { MongoClient } from "https://deno.land/x/mongo/mod.ts"; const DB_URL = "mongodb://localhost:27017" const mongo_client = new MongoClient(); mongo_client.connectWithUri(DB_URL); const db = mongo_client.database('employees_db'); export default db;

Finally to start the server run the bellow command

deno run --allow-net --allow-write --allow-read --allow-plugin --unstable server.ts

Summary So you can see how we build an application using Deno + REST API + Mongodb. Keep explore our site we will again come back with more interesting articles in Deno.

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By the way, want to learn more about Deno? Just check out the official Deno documentation.

Originally published at https://codinghub.net.