دوال النصوص

SELECT CONCAT(first_name, ' ', last_name) AS full_name FROM users;

SELECT name, LENGTH(name) FROM users;

SELECT UPPER(code), LOWER(email) FROM users;

SELECT SUBSTRING(phone, 1, 3) FROM users;  -- أول 3 أحرف

SELECT TRIM('  براء  ');       -- 'براء'
SELECT LTRIM(name), RTRIM(name) FROM users;

SELECT REPLACE(phone, '-', '') FROM users;  -- حذف الشرطات

-- توحيد البريد وإظهار أول حرف من الاسم
SELECT
  CONCAT(LEFT(name, 1), '.') AS initial,
  LOWER(TRIM(email)) AS email
FROM users;