dev-sankhadip

import { StudentDA } from "../DA";
import { IStudent } from "../types/types";
import shortid from "shortid";

export class StudentService {

    constructor(private studentDA: StudentDA) { }
    public async GetStudents() {
        try {
            const data = await this.studentDA.GetStudents();

dev-sankhadip

import { StudentService } from '../service';
import { Router, Response, Request } from 'express';



export const StudentRouter = (router: Router, service: StudentService): void => {
    router.get('/', async (req: Request, res: Response) => {
        try {
            const data = await service.GetStudents();
            res.status(200).send(data)

dev-sankhadip

import express from 'express';
import dotenv from 'dotenv';

import { StudentDA } from './DA/index';
import { StudentService } from './service/index';
import { StudentRouter } from "./routes/index";


dotenv.config();

dev-sankhadip

import { DBManager } from "./DBManager";
import { IStudent } from "../types/types";


export class StudentDA extends DBManager {
    public async GetStudents() {
        const query = "select * from student"
        try {
            const data = await this.ReadData(query);
            return data;

dev-sankhadip

Create table student(id varchar(10), name varchar(50), email varchar(100), age int(5));

dev-sankhadip

{
  "compilerOptions": {
    "target": "es6",
    "module": "commonjs",
    "sourceMap": true,
    "outDir": "./build",
    "rootDir": "./src",
    /* Strict Type-Checking Options */
    "strict": true,
    /* Module Resolution Options */

dev-sankhadip

PORT=3000
HOST='localhost'
USER='root'
PASSWORD='root'
DATABASE='onion'

dev-sankhadip

import { MysqlError } from "mysql";

export interface IDBManager {
    ReadData(query: string, paramCollection: (number | string | boolean)[]): Promise<any | MysqlError>

    InsertOrUpdateData(query: string, paramCollection: (number | string | boolean)[]): Promise<any | MysqlError>

    DeleteData(query: string, paramCollection: (number | string | boolean)[]): Promise<any | MysqlError>
}

dev-sankhadip

import mysql from 'mysql';
import dotenv from 'dotenv'


dotenv.config();
const connection = mysql.createPool({
    host: process.env.HOST,
    user: process.env.USER,
    password: process.env.PASSWORD,
    database: process.env.DATABASE,

dev-sankhadip

import { IDBManager, MySqlType } from "../types/types";
import { connection } from "./DBConnection";

export class DBManager implements IDBManager {

    public ReadData(query: string, paramCollection: (string | number | boolean)[] = []): Promise<MySqlType> {
        return new Promise((resolve, reject) => {
            connection.query(query, paramCollection, (err, result) => {
                if (err) {
                    return reject(err)