String and Date Functions
String Functions
SELECT UPPER(name), LOWER(email) FROM users;
SELECT LENGTH(description) FROM products;
SELECT CONCAT(first_name, ' ', last_name) AS full_name FROM users;
SELECT SUBSTRING(description, 1, 100) FROM products;
SELECT TRIM(name), REPLACE(text, 'old', 'new') FROM posts;
Date Functions
SELECT NOW(); -- current datetime
SELECT CURDATE(); -- current date
SELECT YEAR(created_at) FROM orders;
SELECT MONTH(created_at) FROM orders;
SELECT DATE_FORMAT(created_at, '%d/%m/%Y') FROM orders;
SELECT DATEDIFF('2025-01-01', NOW()) AS days_until;