mongoose 操作 mongodb
最后更新于：2022-04-02 03:30:41
[TOC]
[mongoose 官网](https://mongoosejs.com/docs/validation.html)
[简书参考](https://www.jianshu.com/p/9b20c1e2f373)
## 安装
`npm i -S mongoose`
## demo使用
在`model/base.js `中
连接数据库
```
const mongoose = require("mongoose");
// 若是带账号密码的：'mongodb://root:123456@127.0.0.1:27017/dumall'
const connStr= "mongodb://127.0.0.1:27017/imoocsell";
mongoose.connect(connStr,{ useNewUrlParser: true });
mongoose.connection.on("connected",()=>{
console.log("MongoDB connected success.")
});
mongoose.connection.on("error",()=>{
console.log("MongoDB connected fail.")
});
mongoose.connection.on("disconnected",()=>{
console.log("MongoDB connected disconnected.")
});
```
在`model/goods.js`中
创建 映射关系
```
const mongoose = require("mongoose");
let Schema = mongoose.Schema;
//定义一个shcema
var productSchema = new Schema({
'productId':String, // 或者 'productId':{type:String}
'productName':String,
'salePrice':Number,
'productImage':String,
});
// 输出(导出)
module.exports = mongoose.model('good',productSchema,"goods");//第三参数对应表名
```
在 `routers/goods.js` 中
```
const goods = require("../models/goods");
//复杂条件查询
params.salePrice={
$gt: priceGt,
$lte: priceLte,
}
goodsModel = goods.find(params);
goodsModel.sort({salePrice:param.sort}).skip(skip).limit(param.pageSize);
goodsModel.exec((err,doc)=>{}
//单条查询
User.findOne({userName:userName},(err1,userDoc)=>{
//保存
userDoc.userName="ccc";
userDoc.save((err4,doc3)=>{})
}
//删除用户下购物车中的某个物品
userModel.update({userId: userId},
{$pull: {cartList:
{productId: productId}
}
}, (err, doc) => {})
//更新 购物车下的某个物品数量
userModel.update({
userId:userId,"cartList.productId":productId},
{"cartList.$.productNum":productNum},(err,doc)=>{});
//类更改默认值
userModel.findOne({userId:userId},(err,doc)=>{
doc.addressList.forEach(item=>{}) //进行循环
doc.save((err,doc)=>{})
});
```
##
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