SUBSTR

Syntax

Purpose

SUBSTR returns a portion of char, beginning at character m, n characters long.

• If m is 0, it is treated as 1.

• If m is positive, Oracle counts from the beginning of char to find the first character.

• If m is negative, Oracle counts backwards from the end of char.

• If n is omitted, Oracle returns all characters to the end of char. If n is less than 1, a null is returned.

Floating-point numbers passed as arguments to SUBSTR are automatically converted to integers.

SELECT SUBSTR('ABCDEFG',3,4) "Substring"
     FROM DUAL;
 
Substring
---------
CDEF

Example 2

SELECT SUBSTR('ABCDEFG',-5,4) "Substring"
     FROM DUAL;

Substring
---------
CDEF