oracle '|' substr code example

Example 1: oracle substring

-- 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

Example 2: ORACLE SQL SUBSTR

SUBSTR(string, :START_POS, :SUBSTR_LENGTH);

SELECT SUBSTR('ABCDEFG',3,4) FROM DUAL;
--OUTPUT: CDEF