SELECT name || ' — ' || price || ' ₽' AS tag
FROM products
LIMIT 3;

SELECT concat(name, ', тел. ', phone) AS contact
FROM customers
LIMIT 3;

SELECT upper(name) AS loud, lower(email) AS email
FROM customers
LIMIT 3;

SELECT name, length(name) AS chars
FROM products
ORDER BY chars DESC
LIMIT 3;

SELECT name, left(name, 1) AS initial, substring(email from position('@' in email) + 1) AS domain
FROM customers
WHERE email IS NOT NULL
LIMIT 4;

SELECT email, position('@' in email) AS at
FROM customers
WHERE email IS NOT NULL
LIMIT 3;

SELECT '[' || trim('   Пенал   ') || ']' AS cleaned;

SELECT phone, replace(replace(phone, ' ', ''), '-', '') AS digits
FROM customers
WHERE phone IS NOT NULL;