学生管理系统

let express = require('express');
let app = new express();
let MongoClient = require('mongodb').MongoClient;
let bodyParser = require('body-parser');
var ObjectID =  require("mongodb").ObjectID; //mongo数据库特有的ID

app.use(bodyParser.urlencoded({ extended: false }));
app.use(bodyParser.json());
// 依赖项
app.set('view engine','ejs');
// 查询数据
app.get('/',(req,res)=>{
    res.redirect('/show')
})
app.get('/show',(req,res)=>{
    let URL = 'mongodb://127.0.0.1:27017/stuManger';
    MongoClient.connect(URL,(err,db)=>{
        if(err){
            res.send('数据库链接失败');
            return;
        }
        let collection = db.collection('stu');
        collection.find().toArray((err,data)=>{
           if(!err){
            res.render('showStuinfo',{list:data})
           }
        })
        db.close();
    }); 
})
// 添加数据
app.get('/add',(req,res)=>{
    res.render('add');
})
app.post('/addDo',(req,res)=>{
    let URL = 'mongodb://127.0.0.1:27017/stuManger';
    MongoClient.connect(URL,(err,db)=>{
        if(err){
            res.send('数据库链接失败');
            return;
        };
        let collection = db.collection('stu');
        let stumsg = {
            'sname':req.body.sname,
            'age':req.body.age,
            'address':req.body.address,
            'tel':req.body.tel,
        };
        collection.insert(stumsg,(err,result)=>{
            res.send('<script>alert("添加成功");location.href="/show"</script>');
        });
        db.close();
    });
});
// 删除数据
app.get('/delete',(req,res)=>{
    let URL = 'mongodb://127.0.0.1:27017/stuManger';
    MongoClient.connect(URL,(err,db)=>{
        if(err){
            res.send('数据库链接失败');
            return;
        }
        let collection = db.collection('stu');
        let id = req.query.id;
        collection.remove({'_id':new ObjectID(id)},(err,data)=>{
            res.send('<script>alert("删除成功");location.href="/show"</script>');
        })
        db.close();
    }); 
});
// 修改数据
app.get('/updata',(req,res)=>{
    let URL = 'mongodb://127.0.0.1:27017/stuManger';
    MongoClient.connect(URL,(err,db)=>{
        if(err){
            res.send('数据库链接失败');
            return;
        }
        let collection = db.collection('stu');
        let id = req.query.id;
        collection.find({'_id':new ObjectID(id)}).toArray((err,data)=>{
            res.render('updata',{single:data[0]});
        })
        db.close();
    }); 
});
// 修改数据
app.post('/updataDo',(req,res)=>{
    let URL = 'mongodb://127.0.0.1:27017/stuManger';
    MongoClient.connect(URL,(err,db)=>{
        if(err){
            res.send('数据库链接失败');
            return;
        }
        let collection = db.collection('stu');
        let body = req.body;
        collection.update({'_id':new ObjectID(body.id)},{$set:{'sname':body.sname,'age':body.age,'address':body.address,'tel':body.tel}},(err,data)=>{
            res.send('<script>alert("修改成功");location.href="/show"</script>');
        })
        db.close();
    }); 
});
app.use((req,res)=>{
    res.status(404).send('not Found 404');
});
app.listen(3000,()=>{
    console.log('start');
})