DevOps: What is PostgreSQL?

1-- Table
2CREATE TABLE users (
3  id SERIAL PRIMARY KEY,
4  name VARCHAR(100) NOT NULL,
5  email VARCHAR(255) UNIQUE NOT NULL,
6  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
7);
8
9-- Queries
10SELECT * FROM users WHERE id = 1;
11INSERT INTO users (name, email) VALUES ('Alice', 'a@b.com');
12UPDATE users SET name = 'Bob' WHERE id = 1;
13DELETE FROM users WHERE id = 1;
14
15-- JOIN
16SELECT u.name, p.title
17FROM users u
18JOIN posts p ON u.id = p.user_id;
19
20-- Indexes
21CREATE INDEX idx_users_email ON users(email);
22
23-- Transactions
24BEGIN;
25UPDATE accounts SET balance = balance - 100 WHERE id = 1;
26UPDATE accounts SET balance = balance + 100 WHERE id = 2;
27COMMIT;
28
29-- Export/Import
30pg_dump -U postgres mydb > backup.sql
31psql -U postgres mydb < backup.sql