Работа с базами данных: PostgreSQL, MongoDB, Redis

1npm install pg

1import { Pool } from 'pg';
2
3const pool = new Pool({
4  host: 'localhost',
5  port: 5432,
6  database: 'myapp',
7  user: 'postgres',
8  password: 'password',
9});

1// SELECT
2const { rows } = await pool.query('SELECT * FROM users WHERE id = $1', [1]);
3
4// INSERT
5await pool.query(
6  'INSERT INTO users (name, email) VALUES ($1, $2)',
7  ['Иван', 'ivan@example.com']
8);
9
10// UPDATE
11await pool.query(
12  'UPDATE users SET name = $1 WHERE id = $2',
13  ['Николай', 1]
14);

1npm install prisma @prisma/client

1import { PrismaClient } from '@prisma/client';
2
3const prisma = new PrismaClient();
4
5// Создание
6const user = await prisma.user.create({
7  data: { name: 'Иван', email: 'ivan@example.com' },
8});
9
10// Чтение
11const users = await prisma.user.findMany({
12  where: { name: { contains: 'Иван' } },
13});
14
15// Обновление
16await prisma.user.update({
17  where: { id: 1 },
18  data: { name: 'Николай' },
19});

1npm install mongoose

1import mongoose from 'mongoose';
2
3await mongoose.connect('mongodb://localhost:27017/myapp');

1const userSchema = new mongoose.Schema({
2  name: { type: String, required: true },
3  email: { type: String, required: true, unique: true },
4  age: { type: Number, min: 0 },
5  createdAt: { type: Date, default: Date.now },
6});
7
8const User = mongoose.model('User', userSchema);

1// Создание
2const user = await User.create({ name: 'Иван', email: 'ivan@example.com' });
3
4// Чтение
5const users = await User.find({ name: 'Иван' });
6const user = await User.findById(1);
7
8// Обновление
9await User.findByIdAndUpdate(1, { name: 'Николай' });
10
11// Удаление
12await User.findByIdAndDelete(1);

1npm install redis

1import { createClient } from 'redis';
2
3const client = createClient();
4await client.connect();

1// Set/Get
2await client.set('user:1', JSON.stringify({ name: 'Иван' }));
3const user = JSON.parse(await client.get('user:1'));
4
5// Hash
6await client.hSet('user:1', 'name', 'Иван', 'email', 'ivan@example.com');
7const name = await client.hGet('user:1', 'name');
8
9// List
10await client.lPush('queue', 'task1', 'task2');
11const task = await client.lPop('queue');
12
13// Set
14await client.sAdd('tags', 'javascript', 'nodejs');
15const tags = await client.sMembers('tags');

1async function getUserWithCache(id) {
2  const cached = await client.get(`user:${id}`);
3  if (cached) return JSON.parse(cached);
4
5  const user = await prisma.user.findUnique({ where: { id } });
6  await client.set(`user:${id}`, JSON.stringify(user), { EX: 3600 });
7  return user;
8}

1// Кэширование запросов к PostgreSQL
2async function getCachedUsers() {
3  const cached = await redis.get('users');
4  if (cached) return JSON.parse(cached);
5
6  const users = await prisma.user.findMany();
7  await redis.set('users', JSON.stringify(users), { EX: 300 });
8  return users;
9}

1// Кэширование документов MongoDB
2async function getCachedDocument(id) {
3  const cached = await redis.get(`doc:${id}`);
4  if (cached) return JSON.parse(cached);
5
6  const doc = await Document.findById(id);
7  await redis.set(`doc:${id}`, JSON.stringify(doc), { EX: 600 });
8  return doc;
9}

1npx prisma migrate dev --name init
2npx prisma migrate deploy