Koa_ mySQL_ Integration of TS

Koa_mySQL_Ts Integration of

• Desktop new folder ts_mysql_koa

• Initialize project ：npm init -y

  

• Install some required third-party modules ：npm i koa koa-router koa-bodyparser typescript mysql2

  

• stay package.json Configuration script

  {
        
    "name": "ts_mysql_koa",
    "version": "1.0.0",
    "description": "",
    "main": "index.js",
    "scripts": {
        
      "start": "ts-node-dev ./src/app.ts"
    },
    "keywords": [],
    "author": "",
    "license": "ISC",
    "dependencies": {
        
      "koa": "^2.13.4",
      "koa-bodyparser": "^4.3.0",
      "koa-router": "^10.1.1",
      "mysql2": "^2.3.3",
      "ts-node-dev": "^2.0.0",
      "typescript": "^4.7.4"
    }
  }
  

• Create a new folder in the root directory src, In the folder src Next, create a new folder app.ts As an entry file .

• Build the directory structure of the project

  

• Start by opening Navicat Premium Database development tools , New database mall

  use mall;
  
  CREATE TABLE `user` (
  id INT PRIMARY KEY AUTO_INCREMENT,
  username VARCHAR(20),
  `password` VARCHAR(20),
  nickName VARCHAR(20),
  age INT,
  birthday TIMESTAMP DEFAULT CURRENT_TIMESTAMP
  )
  
  INSERT INTO `user` SET username = 'admin',password = '123456',nickname = ' Zhang San ',age = 18;
  INSERT INTO `user` SET username = 'lisi',password = '123456',nickname = ' Li Si ',age = 18;
  INSERT INTO `user` SET username = 'wangwu',password = '123456',nickname = ' Wang Wu ',age = 18;
  INSERT INTO `user` SET username = 'zhaoliu',password = '123456',nickname = ' Zhao Liu ',age = 18;
  
  SELECT * FROM `user`;
  

• stay config New under folder db.ts Folder

  export default {
        
      host:'localhost',
      port:3306,
      user:'root',
      password:'123456',
      database:'mall'
  }
  

• stay util Create a new file under the folder index.ts（ Encapsulate database operation statements ）

  import {
        createConnection} from "mysql2";
  import config from '../config/db'
  
  //  Get database connection 
  const connection = createConnection(config)
  
  export default class DBUtil {
        
      //  Encapsulate common database operation statements 
      static query(sql:string,params?:any|any[]|{
        [param:string]:any}):Promise<any>{
        
          //  adopt Promise Returns the result of the database operation 
          return new Promise<unknown>((resolve,reject)=>{
        
              //  Execute via database connection sql sentence 
              connection.query(sql,params,(err,result,fields)=>{
        
                  //  Judge sql Is there any error in execution 
                  if(err){
        
                      //  Failure 
                      reject(err)
                  }else {
        
                      //  success 
                      resolve(result
  
                      )
                  }
              })
          })
      }
  }
  

• stay router New under the folder user.ts

  import * as Router from 'koa-router'
  
  import UserService from '../service/user'
  
  const userRouter = new Router({
        prefix:'/user'})
  
  const {
        queryAll,count,queryOne,del,save,edit} = new UserService()
  /** *  Query all  */
  userRouter.get('/',queryAll)
  
  /** *  Query quantity  */
  userRouter.get('/count',count)
  
  /** *  according to id Inquire about  */
  userRouter.get('/:id',queryOne)
  
  /** *  according to id Delete  */
  userRouter.delete('/:id',del)
  
  /** *  add to  */
  userRouter.post('/',save)
  
  /** *  modify  */
  userRouter.patch('/:id',edit)
  
  export default userRouter
  

• stay service New under the folder user.ts

  import UserController from '../controller/user'
  
  const {
        queryAll,getCount,queryOne,del,save,edit} = new UserController()
  
  export default class UserService{
        
      /** *  Query all  * @param ctx */
      async queryAll(ctx):Promise<void>{
        
          const {
        page}=ctx.query
          let currentPage = 1
          if(page && page !='undefined') {
        
              currentPage = (page - 1) * 10
          }
          const res = await queryAll([currentPage,10])
          ctx.body = res
      }
  
      /** *  Number  * @param ctx */
      async count(ctx):Promise<void>{
        
          const [count] = await getCount()
          ctx.body = count
      }
  
      /** *  according to id Inquire about  * @param ctx */
      async queryOne(ctx):Promise<void>{
        
          const {
        id} = ctx.params
          const [res] = await queryOne(id)
          ctx.body = res
      }
  
      /** *  according to id Delete  * @param ctx */
      async del(ctx):Promise<void>{
        
          const {
        id} = ctx.params
          const {
        affectedRows} = await del([id])
          ctx.body = affectedRows?' Delete successful ':' Delete failed '
      }
  
      /** *  add to  * @param ctx */
      async save(ctx):Promise<void>{
        
          const body = ctx.request.body
          const {
        insertId} = await save(body)
          ctx.body = insertId?' Add success ':' Add failure '
      }
  
      /** *  modify  * @param ctx */
      async edit(ctx):Promise<void>{
        
          const body = ctx.request.body
          const {
        id} = ctx.params
          const {
        affectedRows} = await edit([body,id])
          ctx.body = affectedRows?' Modification successful ':' Modification failed '
      }
  }
  

• stay controller New under the folder user.ts

  import DBUtil from '../util'
  
  export default class UserController {
        
      /** *  Query all  * @param params */
      queryAll(params:any){
        
          return DBUtil.query('select * from user limit ?,?',params)
      }
      getCount(){
        
          return DBUtil.query('select count(*) as count from user')
      }
  
      /** *  according to id Inquire about  * @param params */
      queryOne(params:any){
        
          return DBUtil.query('select * from user where id=?',params)
      }
  
      /** *  according to id Delete  * @param params */
      del(params:any){
        
          return DBUtil.query('delete from user where id=?',params)
      }
  
      /** *  add to  * @param params */
      save(params:any){
        
          return DBUtil.query('insert into user set ?',params)
      }
  
      /** *  modify  * @param params */
      edit(params:any){
        
          return DBUtil.query('update user set ? where id=?',params)
      }
  }
  

• According to the Postman Interface test tools test one by one , Unmistakable