Mongoose로 CRUD 작업하기
Mongoose 메서드를 사용해 생성, 조회, 수정, 삭제 작업을 구현하고 데이터를 관리합니다.
Mongoose로 CRUD 작업하기은(는) CoddyKit의 무료 Node.js Backend Development Bootcamp 강의입니다. 이것은 4개 중 3번째 강의입니다. 아래에서 전체 강의를 무료로 읽을 수 있으며, 내장 코드 에디터와 24/7 AI 튜터와 함께 브라우저에서 직접 실습할 수 있습니다. 이 강의는 Node.js Backend Development Bootcamp 학습 경로의 일부이며, 진행 상황이 웹과 CoddyKit 앱에 동기화됩니다. Node.js Backend Development Bootcamp 강의에는 총 4개의 강의가 포함되어 있습니다.
이 강의의 일부는 아직 번역되지 않았으며 영어로 표시됩니다.
What is CRUD?
CRUD stands for Create, Read, Update, and Delete. These are the four fundamental operations you perform on data in almost any database application.
Understanding CRUD is key to building interactive applications where users can manage information.
- Create: Adding new data.
- Read: Retrieving existing data.
- Update: Modifying existing data.
- Delete: Removing data.
Our Sample Mongoose Model
Before we perform CRUD operations, we need a Mongoose model. This model defines the structure of our documents in MongoDB.
We'll use a simple Book model for our examples:
const mongoose = require('mongoose');
const bookSchema = new mongoose.Schema({
title: String,
author: String,
year: Number
});
const Book = mongoose.model('Book', bookSchema);This Book model will interact with a books collection in our database.
Creating New Documents
The "Create" operation adds new documents to your MongoDB collection. With Mongoose, you can create a new instance of your model and then call its .save() method.
Alternatively, use Model.create() for a simpler approach.
const mongoose = require('mongoose');
const bookSchema = new mongoose.Schema({
title: String,
author: String,
year: Number
});
const Book = mongoose.model('Book', bookSchema);
async function main() {
await mongoose.connect('mongodb://localhost:27017/coddykit_db');
console.log('Connected to MongoDB!');
try {
const newBook = new Book({
title: 'The Great Adventure',
author: 'A. Explorer',
year: 2023
});
await newBook.save();
console.log('Book created:', newBook.title);
const anotherBook = await Book.create({
title: 'Node.js Handbook',
author: 'J. Developer',
year: 2022
});
console.log('Book created using create():', anotherBook.title);
} catch (error) {
console.error('Error creating book:', error);
} finally {
await mongoose.disconnect();
console.log('Disconnected from MongoDB.');
}
}
main();Reading All Documents
The "Read" operation retrieves data. To get all documents from a collection, use the Model.find() method without any arguments.
This returns a Mongoose Query object that you can await.
const mongoose = require('mongoose');
const bookSchema = new mongoose.Schema({
title: String,
author: String,
year: Number
});
const Book = mongoose.model('Book', bookSchema);
async function main() {
await mongoose.connect('mongodb://localhost:27017/coddykit_db');
console.log('Connected to MongoDB!');
try {
// Ensure there are some books to read
await Book.deleteMany({}); // Clear existing for clean run
await Book.create([
{ title: 'Book One', author: 'Author A', year: 2000 },
{ title: 'Book Two', author: 'Author B', year: 2010 }
]);
const allBooks = await Book.find();
console.log('All Books:');
allBooks.forEach(book => console.log(`- ${book.title} by ${book.author}`));
} catch (error) {
console.error('Error reading books:', error);
} finally {
await mongoose.disconnect();
console.log('Disconnected from MongoDB.');
}
}
main();Finding Specific Documents
To find documents that match specific criteria, pass a query object to Model.find(). For a single document, use Model.findOne() or Model.findById() if you have its ID.
const mongoose = require('mongoose');
const bookSchema = new mongoose.Schema({
title: String,
author: String,
year: Number
});
const Book = mongoose.model('Book', bookSchema);
async function main() {
await mongoose.connect('mongodb://localhost:27017/coddykit_db');
console.log('Connected to MongoDB!');
try {
await Book.deleteMany({});
const book1 = await Book.create({ title: 'Specific Book', author: 'Jane Doe', year: 2015 });
await Book.create({ title: 'Another Book', author: 'John Smith', year: 2018 });
const foundBookById = await Book.findById(book1._id);
console.log('Found by ID:', foundBookById.title);
const foundBookByTitle = await Book.findOne({ title: 'Another Book' });
console.log('Found by title:', foundBookByTitle.title);
const booksByAuthor = await Book.find({ author: 'Jane Doe' });
console.log('Books by Jane Doe:', booksByAuthor.length);
} catch (error) {
console.error('Error finding specific books:', error);
} finally {
await mongoose.disconnect();
console.log('Disconnected from MongoDB.');
}
}
main();Updating Documents Easily
The "Update" operation modifies existing documents. Mongoose provides methods like Model.findByIdAndUpdate() and Model.updateOne() for this.
findByIdAndUpdate() is convenient for updating a document by its unique ID.
const mongoose = require('mongoose');
const bookSchema = new mongoose.Schema({
title: String,
author: String,
year: Number
});
const Book = mongoose.model('Book', bookSchema);
async function main() {
await mongoose.connect('mongodb://localhost:27017/coddykit_db');
console.log('Connected to MongoDB!');
try {
await Book.deleteMany({});
const createdBook = await Book.create({ title: 'Old Title', author: 'Original Author', year: 2000 });
console.log('Original Book:', createdBook.title);
const updatedBook = await Book.findByIdAndUpdate(
createdBook._id,
{ title: 'New & Improved Title', year: 2024 },
{ new: true } // Return the updated document
);
console.log('Updated Book:', updatedBook.title, 'Year:', updatedBook.year);
} catch (error) {
console.error('Error updating book:', error);
} finally {
await mongoose.disconnect();
console.log('Disconnected from MongoDB.');
}
}
main();Manual Update & Save
Another way to update is to first find the document, modify its properties, and then call its .save() method. This is useful when you need to perform logic on the document before saving.
It triggers Mongoose middleware (like pre-save hooks) unlike `findByIdAndUpdate` by default.
const mongoose = require('mongoose');
const bookSchema = new mongoose.Schema({
title: String,
author: String,
year: Number
});
const Book = mongoose.model('Book', bookSchema);
async function main() {
await mongoose.connect('mongodb://localhost:27017/coddykit_db');
console.log('Connected to MongoDB!');
try {
await Book.deleteMany({});
const createdBook = await Book.create({ title: 'To Be Modified', author: 'Someone', year: 2010 });
console.log('Original Book:', createdBook.title);
const bookToModify = await Book.findById(createdBook._id);
if (bookToModify) {
bookToModify.title = 'Modified Title with Save';
bookToModify.year = 2011;
await bookToModify.save();
console.log('Modified Book:', bookToModify.title, 'Year:', bookToModify.year);
}
} catch (error) {
console.error('Error modifying and saving book:', error);
} finally {
await mongoose.disconnect();
console.log('Disconnected from MongoDB.');
}
}
main();Deleting Documents
The "Delete" operation removes documents from your collection. Mongoose offers methods like Model.findByIdAndDelete() and Model.deleteOne() or Model.deleteMany().
Use these carefully as deletions are usually permanent!
const mongoose = require('mongoose');
const bookSchema = new mongoose.Schema({
title: String,
author: String,
year: Number
});
const Book = mongoose.model('Book', bookSchema);
async function main() {
await mongoose.connect('mongodb://localhost:27017/coddykit_db');
console.log('Connected to MongoDB!');
try {
await Book.deleteMany({});
const bookToDelete = await Book.create({ title: 'Ephemeral Book', author: 'Ghost', year: 2020 });
await Book.create({ title: 'Another One', author: 'Someone Else', year: 2021 });
console.log('Books before delete:', (await Book.find()).length);
await Book.findByIdAndDelete(bookToDelete._id);
console.log('Book deleted by ID.');
console.log('Books after delete:', (await Book.find()).length);
await Book.deleteOne({ title: 'Another One' });
console.log('Another book deleted by criteria.');
console.log('Books after second delete:', (await Book.find()).length);
} catch (error) {
console.error('Error deleting book:', error);
} finally {
await mongoose.disconnect();
console.log('Disconnected from MongoDB.');
}
}
main();Asynchronous Operations
All Mongoose CRUD operations are asynchronous. This means they don't block the main thread while waiting for the database.
Always use async/await or Promises (.then()/.catch()) to handle their results and potential errors.
Proper error handling ensures your application is robust and user-friendly.
CRUD Quick Check
Consider the following Mongoose model and code snippet:
const userSchema = new mongoose.Schema({
username: String,
email: String
});
const User = mongoose.model('User', userSchema);
// ... connection established ...
async function performAction() {
const newUser = await User.create({ username: 'coder', email: 'coder@example.com' });
newUser.username = 'pro_coder';
await newUser.save();
console.log(newUser.username);
}
performAction();What will be logged to the console?
CRUD Operations Summary
You've learned the essential CRUD operations with Mongoose!
- Create: Use
new Model().save()orModel.create(). - Read: Use
Model.find(),Model.findOne(), orModel.findById(). - Update: Use
Model.findByIdAndUpdate()or find, modify, then.save(). - Delete: Use
Model.findByIdAndDelete()orModel.deleteOne().
These operations form the backbone of almost any data-driven application.
자주 묻는 질문
“Mongoose로 CRUD 작업하기” 강의는 무료인가요?
네 — “Mongoose로 CRUD 작업하기” 전체 내용을 이 웹사이트에서 무료로 읽을 수 있습니다. 인터랙티브하게 실습하려면(내장 코드 에디터와 24/7 AI 튜터), CoddyKit PRO로 업그레이드하면 Node.js Backend Development Bootcamp 강의 전체를 잠금 해제할 수 있습니다. Node.js Backend Development Bootcamp 강의에는 총 4개의 강의가 포함되어 있습니다.
“Mongoose로 CRUD 작업하기”에서 뭘 배우나요?
Mongoose 메서드를 사용해 생성, 조회, 수정, 삭제 작업을 구현하고 데이터를 관리합니다. 브라우저에서 직접 실행하는 실습 코드로 Node.js Backend Development Bootcamp을(를) 배우며, 24/7 AI 튜터가 강의를 진행하면서 질문에 답변해줍니다.
Node.js Backend Development Bootcamp을(를) 시작하는 데 경험이 필요한가요?
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이 강의의 모든 강의
- Node.js를 MongoDB에 연결하기
- 데이터 모델링을 위한 Mongoose ODM
- Mongoose로 CRUD 작업하기
- Mongoose로 데이터 조회 및 필터링