CREATE FUNCTION linear_equation AS (x, k, b) -> k*x + b;
SELECT number, linear_equation(number, 2, 1) FROM numbers(3);

SELECT
    number,
    linear_equation(number, 2, 1)
FROM numbers(3)

Query id: 9a4a2978-b186-4bc2-ac0c-86daf0328212

┌─number─┬─plus(multiply(2, number), 1)─┐
│      0 │                            1 │
│      1 │                            3 │
│      2 │                            5 │
└────────┴──────────────────────────────┘

3 rows in set. Elapsed: 0.002 sec. 

CREATE FUNCTION parity_str AS (n) -> if(n % 2, 'odd', 'even');
SELECT number, parity_str(number) FROM numbers(3);

SELECT
    number,
    parity_str(number)
FROM numbers(3)

Query id: 59a97a32-15c4-4417-8444-51cb00a01ac0

┌─number─┬─if(modulo(number, 2), 'odd', 'even')─┐
│      0 │ even                                 │
│      1 │ odd                                  │
│      2 │ even                                 │
└────────┴──────────────────────────────────────┘

3 rows in set. Elapsed: 0.002 sec.