String Functions
UPPER / LOWER
SELECT UPPER('hello'); -- 'HELLO'SELECT LOWER('HELLO'); -- 'hello'LENGTH / CHAR_LENGTH
SELECT LENGTH('hello'); -- 5SELECT CHAR_LENGTH('hello'); -- 5TRIM / LTRIM / RTRIM
SELECT TRIM(' hello '); -- 'hello'SELECT LTRIM(' hello'); -- 'hello'SELECT RTRIM('hello '); -- 'hello'SUBSTR / SUBSTRING
SELECT SUBSTR('hello world', 1, 5); -- 'hello'SELECT SUBSTR('hello', 3); -- 'llo'CONCAT / ||
SELECT CONCAT('hello', ' ', 'world'); -- 'hello world'SELECT 'hello' || ' ' || 'world'; -- 'hello world'REPLACE
SELECT REPLACE('hello world', 'world', 'TensorDB'); -- 'hello TensorDB'INSTR
SELECT INSTR('hello world', 'world'); -- 7REVERSE
SELECT REVERSE('hello'); -- 'olleh'REPEAT
SELECT REPEAT('ab', 3); -- 'ababab'LEFT / RIGHT
SELECT LEFT('hello', 3); -- 'hel'SELECT RIGHT('hello', 3); -- 'llo'LPAD / RPAD
SELECT LPAD('42', 5, '0'); -- '00042'SELECT RPAD('hi', 5, '.'); -- 'hi...'COALESCE
SELECT COALESCE(NULL, NULL, 'default'); -- 'default'NULLIF
SELECT NULLIF('a', 'a'); -- NULLSELECT NULLIF('a', 'b'); -- 'a'TYPEOF
SELECT TYPEOF(42); -- 'integer'SELECT TYPEOF('hello'); -- 'text'SELECT TYPEOF(3.14); -- 'real'