1.安装 express
npm i express --save
2.安装 mongoDB
npm i mongodb --save
3.安装mongoose
npm i mongoose --save
4.server.js中创建schema，shcema相当于sql的表，里面含有字段，可以定义自定类型，如String，Number等类型，
var schema = new mongoose.Schema({ userName:{type:String,require:true}, age:{type:Number,require:true} });
5.创建model 。mongoose("自定义schema的名称",刚创建的schema)
var User = mongoose.model("user",sechma);
6.创建数据
User.create({ userName:"ls", age:13 },function(err,doc){ if(!err){ console.log(doc) }else{ console.log(err) } });
7.创建成功后运行 nodemon server.js ,会出现新添加的数据，如下图：
运行后，要注释第6步的代码，不然会重复创建数据
8.server.js完整代码：
const express = require('express');
const mongoose = require("mongoose");
const app = express();
const DB_URL = "mongodb://localhost:27017"
mongoose.connect(DB_URL);
mongoose.connection.on("connected",function(){
console.log("connect success");
});
var schema = new mongoose.Schema({
userName:{type:String,require:true},
age:{type:Number,require:true},
});
var User = mongoose.model("user",schema);
User.create({
userName:"ls",
age:13
},function(err,doc){
if(!err){
console.log(doc);
}else{
console.log(err);
}
});
app.get("/",function(req,res){
res.send("test");
});
app.get("/data",function(req,res){
res.json({
name:"zs",
age:12
});
});
app.listen(9090,function(){
console.log("listening port 9090");
});
