Database Integration với MongoDB

Mongoose ODM

Kết nối MongoDB

const mongoose = require('mongoose');

const connectDB = async () => {
  try {
    const conn = await mongoose.connect(process.env.MONGODB_URI, {
      useNewUrlParser: true,
      useUnifiedTopology: true,
    });
    console.log(`MongoDB Connected: ${conn.connection.host}`);
  } catch (error) {
    console.error('Database connection error:', error);
    process.exit(1);
  }
};

module.exports = connectDB;

Tạo Schema và Model

const userSchema = new mongoose.Schema({
  name: {
    type: String,
    required: [true, 'Please add a name'],
    trim: true,
    maxlength: [50, 'Name cannot be more than 50 characters']
  },
  email: {
    type: String,
    required: [true, 'Please add an email'],
    unique: true,
    lowercase: true,
    match: [
      /^w+([.-]?w+)*@w+([.-]?w+)*(.w{2,3})+$/,
      'Please add a valid email'
    ]
  },
  password: {
    type: String,
    required: [true, 'Please add a password'],
    minlength: 6,
    select: false
  },
  role: {
    type: String,
    enum: ['user', 'admin'],
    default: 'user'
  }
}, {
  timestamps: true
});

// Instance method
userSchema.methods.getSignedJwtToken = function() {
  return jwt.sign({ id: this._id }, process.env.JWT_SECRET, {
    expiresIn: process.env.JWT_EXPIRE
  });
};

module.exports = mongoose.model('User', userSchema);

CRUD Operations với Mongoose

Tạo và Đọc

// Create user
const createUser = asyncHandler(async (req, res) => {
  const user = await User.create(req.body);
  res.status(201).json({
    success: true,
    data: user
  });
});

// Get all users với filtering, sorting, pagination
const getUsers = asyncHandler(async (req, res) => {
  // Copy req.query
  const reqQuery = { ...req.query };

  // Fields to exclude
  const removeFields = ['select', 'sort', 'page', 'limit'];
  removeFields.forEach(param => delete reqQuery[param]);

  // Create query string
  let queryStr = JSON.stringify(reqQuery);
  queryStr = queryStr.replace(/(gt|gte|lt|lte|in)/g, match => `$${match}`);

  // Finding resource
  let query = User.find(JSON.parse(queryStr));

  // Select fields
  if (req.query.select) {
    const fields = req.query.select.split(',').join(' ');
    query = query.select(fields);
  }

  // Sort
  if (req.query.sort) {
    const sortBy = req.query.sort.split(',').join(' ');
    query = query.sort(sortBy);
  } else {
    query = query.sort('-createdAt');
  }

  // Pagination
  const page = parseInt(req.query.page, 10) || 1;
  const limit = parseInt(req.query.limit, 10) || 25;
  const startIndex = (page - 1) * limit;
  const endIndex = page * limit;
  const total = await User.countDocuments();

  query = query.skip(startIndex).limit(limit);

  // Executing query
  const users = await query;

  // Pagination result
  const pagination = {};
  if (endIndex < total) {
    pagination.next = { page: page + 1, limit };
  }
  if (startIndex > 0) {
    pagination.prev = { page: page - 1, limit };
  }

  res.status(200).json({
    success: true,
    count: users.length,
    pagination,
    data: users
  });
});

Bài tập thực hành

Hãy tạo CRUD API với MongoDB!