MongoDBMongoDB

// 연결
const { MongoClient } = require('mongodb');
const client = new MongoClient('mongodb://localhost:27017');
const db = client.db('shop');
const col = db.collection('products');

// 생성
await col.insertOne({ name: 'Apple', price: 1500, stock: 100 });
await col.insertMany([
    { name: 'Banana', price: 800 },
    { name: 'Cherry', price: 3000 }
]);

// 조회
const product = await col.findOne({ name: 'Apple' });
const cheap = await col.find({ price: { $lt: 2000 } }).toArray();

// 수정
await col.updateOne({ name: 'Apple' }, { $set: { price: 1600 } });
await col.updateMany({}, { $inc: { stock: -1 } });  // 전체 재고 -1

// 삭제
await col.deleteOne({ stock: { $lte: 0 } });

const result = await col.aggregate([
    { $match: { price: { $gt: 1000 } } },
    { $group: { _id: '$category', avgPrice: { $avg: '$price' } } },
    { $sort: { avgPrice: -1 } }
]).toArray();