psql & Basic Queries (CRUD)

Using the psql CLI

psql is the default Postgres command-line tool.

# Connect
psql -U app_user -d app_db

\l       -- list databases
\c app_db -- connect to database
\dt      -- list tables
\d users -- describe table
\q       -- quit

CRUD Basics

-- Create (INSERT)
INSERT INTO users (name, email)
VALUES ('Linus', 'linus@example.com');

-- Read (SELECT)
SELECT id, name, email FROM users
WHERE email LIKE '%@example.com'
ORDER BY created_at DESC
LIMIT 10;

-- Update
UPDATE users
SET name = 'Linus Torvalds'
WHERE email = 'linus@example.com';

-- Delete
DELETE FROM users
WHERE email = 'linus@example.com';