diff --git a/app/app.js b/app/app.js
new file mode 100644
index 0000000..2a4acea
--- /dev/null
+++ b/app/app.js
@@ -0,0 +1,17 @@
+const Koa = require('koa')
+const logger = require('koa-morgan')
+const router = require('./router')
+const koaBody = require('koa-body')
+
+const app = new Koa()
+
+app
+.use(logger('":method :url" :status :res[content-length] ":referrer" ":user-agent"'))
+.use(koaBody())
+.use(router.routes())
+
+app.listen(3003, () => {
+    console.log("Server is listening on port 3003");
+})
+
+module.exports = app
diff --git a/app/controller.js b/app/controller.js
new file mode 100644
index 0000000..6903dc1
--- /dev/null
+++ b/app/controller.js
@@ -0,0 +1,76 @@
+const Player = require('./schema')
+
+function response(code,mess,data){
+    return{
+        code: code,
+        mess: mess,
+        data: data
+    }
+}
+
+exports.get_player = async (ctx, next) => {
+    let { id } = ctx.params
+    if(!id)
+        ctx.body = response(400,'Invalid ID supplied')
+    id = Number(id)
+    let player = await Player.findOne({id},{_id:0,__v:0})
+    if(player){
+        ctx.body = response(200,'successful operation',player)
+    }else
+        ctx.body = response(404,'Player not found')
+}
+
+exports.add_player = async (ctx, next) => {
+    let { id,name,position } = ctx.request.body
+    if(!id || name || position)
+        ctx.body = response(405,'Invalid input')
+
+    id = Number(id)
+    name = String(name)
+    position = String(position)
+    let player = await Player.findOne({id,name,position})
+    if(player)
+        ctx.body = response(405,'player has already existed')
+
+    let players = new Player({
+        id,name,position
+    })
+    await players.save()
+    let result = await Player.findOne({id,name,position},{_id:0,__v:0})
+    ctx.body = response(200,'successful operation',result)
+}
+
+exports.edit_player = async (ctx, next) => {
+    let { id,name,position } = ctx.request.body
+    if(!id)
+        ctx.body = response(400,'Invalid ID supplied')
+
+    id = Number(id)
+    let player = await Player.find({id})
+    if(player.length<0)
+        ctx.body = response(404,'Player not found')
+
+    let result = await Player.update({id},{name,position})
+    if(result.nModified>0){
+        ctx.body = response(200,'successful operation')
+    }else{
+        ctx.body = response(405,'Validation exception')
+    }
+}
+
+exports.del_player = async (ctx, next) => {
+    let { id } = ctx.params
+    if(!id)
+        ctx.body = response(400,'Invalid ID supplied')
+
+    id = Number(id)
+    let player = await Player.findOne({id})
+    if(!player)
+        ctx.body = response(404,'Player not found')
+    let result = await Player.deleteOne({id})
+    if(result.deletedCount>0){
+        ctx.body = response(200,'successful operation') 
+    }else{
+        ctx.body = response(200,'failed operation',)
+    } 
+}
\ No newline at end of file
diff --git a/app/db.js b/app/db.js
new file mode 100644
index 0000000..0b2e3a7
--- /dev/null
+++ b/app/db.js
@@ -0,0 +1,14 @@
+const mongoose = require('mongoose');
+
+mongoose.connect('mongodb://127.0.0.1:27017/wuqiao', {
+        useNewUrlParser: true
+    })
+    .then(
+        () => {
+            console.log('数据库连接成功')
+        },
+        err => {
+            console.log(`数据库连接失败${err}`)
+        }
+    )
+module.exports = mongoose
\ No newline at end of file
diff --git a/app/package.json b/app/package.json
index 6b480b3..658bc4c 100755
--- a/app/package.json
+++ b/app/package.json
@@ -5,12 +5,16 @@
   "description": "Building a RESTful CRUD API with Node.js, Express/Koa and MongoDB.",
   "main": "server.js",
   "scripts": {
-    "start": "NODE_ENV=development node server.js",
+    "start": " node app.js",
     "start:prod": "NODE_ENV=production node server.js",
     "test": "echo \"Error: no test specified\" && exit 1"
   },
   "dependencies": {
     "express": "^4.17.1",
+    "koa": "^2.11.0",
+    "koa-body": "^4.1.1",
+    "koa-morgan": "^1.0.1",
+    "koa-router": "^8.0.8",
     "mongoose": "^5.9.2"
   },
   "devDependencies": {
diff --git a/app/router.js b/app/router.js
new file mode 100644
index 0000000..34eea57
--- /dev/null
+++ b/app/router.js
@@ -0,0 +1,10 @@
+const Router = require('koa-router')
+const player = require('./controller')
+
+const router = new Router()
+router.post('/player',player.add_player)
+router.get('/player/:id',player.get_player)
+router.put('/player',player.edit_player)
+router.delete('/player/:id',player.del_player)
+
+module.exports = router
\ No newline at end of file
diff --git a/app/schema.js b/app/schema.js
new file mode 100644
index 0000000..ff19793
--- /dev/null
+++ b/app/schema.js
@@ -0,0 +1,17 @@
+const mongoose = require('./db');
+const Schema = mongoose.Schema;
+
+const playerSchema = new Schema({
+
+    id: Number,
+    name: {
+        type: String,
+        required: true
+    },
+    position: {
+        type: String,
+        enum: ['C', 'PF', 'SF', 'PG', 'SG']
+    }
+})
+const Plyaer = mongoose.model('player', playerSchema)
+module.exports = Plyaer
\ No newline at end of file
diff --git a/app/server.js b/app/server.js
deleted file mode 100755
index 72e5b39..0000000
--- a/app/server.js
+++ /dev/null
@@ -1,11 +0,0 @@
-const express = require('express');
-
-const app = express();
-
-app.get('/', (req, res) => {
-    res.json({"message": "Building a RESTful CRUD API with Node.js, Express/Koa and MongoDB."});
-});
-
-app.listen(3000, () => {
-  console.log("Server is listening on port 3000");
-});
\ No newline at end of file