mongoose cheat sheet

Insert

console.log("mongo db connection");

const mongoose = require("mongoose");

const conn_str = "mongodb://localhost:27017/tcet";
mongoose.connect(conn_str, { useNewUrlParser: true, useUnifiedTopology: true })
	.then( () => console.log("Connected Successfully..."))
	.catch( (error) => console.log(error));
	
//schema defining for collection
const teacherSchema = new mongoose.Schema({
	name: {
		type: String,
		required: true
	},
	age: Number,
	city: String
})

// create collection
const Teacher = new mongoose.model("Teacher", teacherSchema);
console.log(Teacher);
	
/*insertOne
const t1 = new Teacher({name: "Shailesh", age: 32, city: "Nagpur"});
console.log(t1.save());


//insertOne
const insertOne = async () => {
	try {
		const t2 = new Teacher({name: "Amy", age: 32, city: "Nagpur"});
		const result = await t2.save();
		console.log(result);
	} catch(e) {
		console.log(e);
	}
};

insertOne();


//insertMany
const insertMany = async () => {
	try {
		const t1 = new Teacher({name: "Amy1", age: 32, city: "Nagpur"});
		const t2 = new Teacher({name: "Amy2", age: 32, city: "Nagpur"});
		const t3 = new Teacher({name: "Amy3", age: 32, city: "Nagpur"});
		const result = await Teacher.insertMany([t1,t2,t3]);
		console.log(result);
	} catch(e) {
		console.log(e);
	}
};

insertMany();
*/

Connection Module

const mongoose = require("mongoose");

const conn_str = "mongodb://localhost:27017/tcet";
mongoose.connect(conn_str, { useNewUrlParser: true, useUnifiedTopology: true })
	.then( () => console.log("Connected Successfully..."))
	.catch( (error) => console.log(error));
	
//schema defining for collection
const teacherSchema = new mongoose.Schema({
	name: {
		type: String,
		required: true
	},
	age: Number,
	city: String
})

// create collection
const Teacher = new mongoose.model("Teacher", teacherSchema);

exports.Teacher = Teacher;

Read

var teacher = require("./teacher");
const Teacher = teacher.Teacher;

/*
const t1 = new Teacher({name: "Penny", age: 25, city: "Nagpur"});
console.log(t1.save());
*/

const getData = async () => {
const data = await Teacher.find({name: /l/i}).select({_id: 0, __v: 0}).limit(2).sort({name: -1});
	console.log(data);
}

getData();

Update

var teacher = require("./teacher");
const Teacher = teacher.Teacher;

/*
const updateOne = async (oname, nname) => {
	try {
		var res = await Teacher.updateOne({name: oname}, {
			$set : { name : nname }
		});
		console.log(res);
	} catch (e) {
		console.log(e);
	}
}

updateOne("Howa", "Kuwa.....");

const updateMany = async (city) => {
	try {
		var res = await Teacher.updateMany({age: {$lt: 30}}, {
			$set : { city : city }
		});
		console.log(res);
	} catch (e) {
		console.log(e);
	}
}

updateMany("Mumbai");

*/

Delete

var teacher = require("./teacher");
const Teacher = teacher.Teacher;

/*
const deleteMany = async (where) => {
	try {
		var res = await Teacher.deleteMany(where);
		console.log(res);
	} catch(error) {
		console.log(error);
	}
}

deleteMany({age : {$in: [25, 37]}});
*/