-- ORACLE substr(string, start, [, length ])
SELECT substr('Hello World', 4, 5) FROM DUAL; -- lo Wo
SELECT substr('Hello World', 4) FROM DUAL; -- lo World
SELECT substr('Hello World', -3) FROM DUAL; -- rld
SELECT substr('Hello World', -3, 2) FROM DUAL; -- rl
-- ORACLE SQL - Get the 2 digits at the right end of a string
SELECT SUBSTR('TN0001234567890345',-2) FROM DUAL;