Mongoose 應用 隨筆

第一步，安裝mongoose模塊

npm i mongoose -S

 

第二步，導入模塊

const mongoose = require("mongoose");

 

 

第三步，鏈接數據庫

mongoose.connect("mongodb://127.0.0.1/tyqaq");//（ps：tyqaq是庫名）

 

其餘步，添加些監聽
得到獲取數據庫鏈接

const conn = mongoose.connection;

 

添加監聽數據庫鏈接事件

conn.on("connected",()=> {
console.log("數據庫鏈接成功")
})

 

Events:（其餘事件）

connecting: Emitted when connection.{open,openSet}() is executed on this connection.
connected: Emitted when this connection successfully connects to the db. May be emitted multiple times in reconnected scenarios.
open: Emitted after we connected and onOpen is executed on all of this connections models.
disconnecting: Emitted when connection.close() was executed.
disconnected: Emitted after getting disconnected from the db.
close: Emitted after we disconnected and onClose executed on all of this connections models.
reconnected: Emitted after we connected and subsequently disconnected, followed by successfully another successfull connection.
error: Emitted when an error occurs on this connection.
fullsetup: Emitted in a replica-set scenario, when primary and at least one seconaries specified in the connection string are connected.
all: Emitted in a replica-set scenario, when all nodes specified in the connection string are connected.
For practical reasons, a Connection equals a Db.

第四步，建立數據模型（集合，表）

exports.User = mongoose.model("users",{
account:String,
password:String,
photo:String,
createTime:Date,
ip:String
});

 

或者這樣寫

// name : { type:String },//屬性name,類型爲String
// age : { type:Number, default:0 },//屬性age,類型爲Number,默認爲0

 

查找&&寫入數據

router.post("/api/user/register", (req, res) => {
// 查找集合內account字段 有多少個 若是大於0表示帳戶存在，也就不寫入
db.User.find({ account: req.body.account }).count(function (err, count) {
if (count > 0) {
res.json({ code: "fail", message: "賬戶名存在！" })
} else {

//不大於0表示不存在 準備導入庫
req.body.createTime = new Date();
req.body.ip = tools.formatIP(req.ip);

// 使用數據模型類建立一個用戶對象，而且填充數據
var user = new db.User(req.body);

// 調用save方法將數據保存到數據庫中
// 數據模型表示一類事物，它能夠包含數據，還包含相應的數據操做方法
user.save(function (err, model, count) {
// console.log(arguments);
if (err) {
res.json({ code: "error", message: "服務端錯誤，請稍候在試！" })
} else {
res.json({ code: "success", message: "註冊成功！" })
}
})
}
})
})

 

 

//建立一個篩選對象
var filter = {
account:req.body.account,
password:req.body.password
}
// 根據篩選條件查找。執行回調函數，
db.User.find(filter).exec(function (err,models) {

err存在數據庫出錯，不存在查看 models裏包含內容